diff --git a/fastcore/_nbdev.py b/fastcore/_nbdev.py
index dccc6cbc..af4012af 100644
--- a/fastcore/_nbdev.py
+++ b/fastcore/_nbdev.py
@@ -150,6 +150,7 @@
          "save_config_file": "02_foundation.ipynb",
          "read_config_file": "02_foundation.ipynb",
          "Config": "02_foundation.ipynb",
+         "working_dir": "03_xtras.ipynb",
          "walk": "03_xtras.ipynb",
          "globtastic": "03_xtras.ipynb",
          "maybe_open": "03_xtras.ipynb",
diff --git a/fastcore/xtras.py b/fastcore/xtras.py
index 979ade63..9e81035e 100644
--- a/fastcore/xtras.py
+++ b/fastcore/xtras.py
@@ -4,12 +4,12 @@
 from __future__ import annotations
 
 
-__all__ = ['walk', 'globtastic', 'maybe_open', 'image_size', 'bunzip', 'loads', 'loads_multi', 'dumps', 'untar_dir',
-           'repo_details', 'run', 'open_file', 'save_pickle', 'load_pickle', 'dict2obj', 'obj2dict', 'repr_dict',
-           'is_listy', 'mapped', 'IterLen', 'ReindexCollection', 'get_source_link', 'truncstr', 'spark_chars',
-           'sparkline', 'modify_exception', 'round_multiple', 'str2bool', 'set_num_threads', 'join_path_file',
-           'autostart', 'EventTimer', 'stringfmt_names', 'PartialFormatter', 'partial_format', 'utc2local', 'local2utc',
-           'trace', 'modified_env', 'ContextManagers', 'shufflish']
+__all__ = ['working_dir', 'walk', 'globtastic', 'maybe_open', 'image_size', 'bunzip', 'loads', 'loads_multi', 'dumps',
+           'untar_dir', 'repo_details', 'run', 'open_file', 'save_pickle', 'load_pickle', 'dict2obj', 'obj2dict',
+           'repr_dict', 'is_listy', 'mapped', 'IterLen', 'ReindexCollection', 'get_source_link', 'truncstr',
+           'spark_chars', 'sparkline', 'modify_exception', 'round_multiple', 'str2bool', 'set_num_threads',
+           'join_path_file', 'autostart', 'EventTimer', 'stringfmt_names', 'PartialFormatter', 'partial_format',
+           'utc2local', 'local2utc', 'trace', 'modified_env', 'ContextManagers', 'shufflish']
 
 # Cell
 #nbdev_comment from __future__ import annotations
@@ -24,6 +24,16 @@
 from contextlib import contextmanager,ExitStack
 from datetime import datetime, timezone
 
+# Cell
+@contextmanager
+def working_dir(path:Path|str, # path to temporarily change the working directory to
+               ):
+    "Changes working directory and returns to previous on exit."
+    prev_cwd = Path.cwd()
+    os.chdir(path)
+    try: yield
+    finally: os.chdir(prev_cwd)
+
 # Cell
 def walk(
     path:Path|str, # path to start searching
diff --git a/nbs/03_xtras.ipynb b/nbs/03_xtras.ipynb
index 0e617f58..6fc9531e 100644
--- a/nbs/03_xtras.ipynb
+++ b/nbs/03_xtras.ipynb
@@ -2,7 +2,7 @@
  "cells": [
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 1,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -11,7 +11,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 2,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -21,7 +21,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 3,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -38,7 +38,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 4,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -63,7 +63,62 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "## File Functions"
+    "## File Functions\n",
+    "\n",
+    "A Context Manager For Changing Directories"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 5,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "#export\n",
+    "@contextmanager\n",
+    "def working_dir(path:Path|str, # path to temporarily change the working directory to\n",
+    "               ):\n",
+    "    \"Changes working directory and returns to previous on exit.\"\n",
+    "    prev_cwd = Path.cwd()\n",
+    "    os.chdir(path)\n",
+    "    try: yield\n",
+    "    finally: os.chdir(prev_cwd)"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 6,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "/Users/hamel/github/fastcore/fastcore\n",
+      "/Users/hamel/github/fastcore/nbs\n"
+     ]
+    }
+   ],
+   "source": [
+    "with working_dir('../fastcore/'):\n",
+    "    print(os.getcwd())\n",
+    "print(os.getcwd())"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 7,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "#hide\n",
+    "_cwd = os.getcwd()\n",
+    "with working_dir('../fastcore/'):\n",
+    "    _cwd_temp = os.getcwd()\n",
+    "    assert _cwd_temp != _cwd\n",
+    "    \n",
+    "_cwd_after = os.getcwd()\n",
+    "assert _cwd == _cwd_after"
    ]
   },
   {
@@ -75,7 +130,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 8,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -97,7 +152,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 9,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -134,7 +189,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 10,
    "metadata": {},
    "outputs": [
     {
@@ -143,7 +198,7 @@
        "(#9) ['./08_script.ipynb','./04_dispatch.ipynb','./06_docments.ipynb','./01_basics.ipynb','./fastcore/docments.py','./fastcore/dispatch.py','./fastcore/basics.py','./fastcore/docscrape.py','./fastcore/script.py']"
       ]
      },
-     "execution_count": null,
+     "execution_count": 10,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -154,7 +209,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 11,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -176,7 +231,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 12,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -198,7 +253,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 13,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -231,7 +286,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 14,
    "metadata": {},
    "outputs": [
     {
@@ -240,7 +295,7 @@
        "'jpeg'"
       ]
      },
-     "execution_count": null,
+     "execution_count": 14,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -259,7 +314,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 15,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -279,7 +334,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 16,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -295,7 +350,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 17,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -311,7 +366,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 18,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -320,7 +375,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 19,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -351,7 +406,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 20,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -360,7 +415,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 21,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -378,7 +433,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 22,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -393,7 +448,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 23,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -408,7 +463,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 24,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -427,7 +482,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 25,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -445,7 +500,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 26,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -460,7 +515,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 27,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -474,7 +529,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 28,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -499,7 +554,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 29,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -522,7 +577,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 30,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -539,7 +594,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 31,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -555,7 +610,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 32,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -565,7 +620,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 33,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -579,7 +634,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 34,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -589,7 +644,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 35,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -627,7 +682,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 36,
    "metadata": {},
    "outputs": [
     {
@@ -636,7 +691,7 @@
        "'pip 21.2.4 from /Users/hamel/opt/anaconda3/lib/python3.9/site-packages/pip (python 3.9)'"
       ]
      },
-     "execution_count": null,
+     "execution_count": 36,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -649,7 +704,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 37,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -672,7 +727,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 38,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -691,7 +746,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 39,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -704,7 +759,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 40,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -722,7 +777,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 41,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -735,7 +790,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 42,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -748,7 +803,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 43,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -772,7 +827,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 44,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -793,7 +848,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 45,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -812,7 +867,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 46,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -823,7 +878,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 47,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -844,7 +899,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 48,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -854,7 +909,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 49,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -869,7 +924,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 50,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -881,7 +936,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 51,
    "metadata": {},
    "outputs": [
     {
@@ -901,7 +956,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 52,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -913,7 +968,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 53,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -926,7 +981,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 54,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -938,7 +993,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 55,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -965,7 +1020,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 56,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -978,7 +1033,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 57,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -991,7 +1046,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 58,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1005,7 +1060,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 59,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1018,16 +1073,16 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 60,
    "metadata": {},
    "outputs": [
     {
      "data": {
       "text/plain": [
-       "Path('/home/jhoward/git/fastcore/fastcore')"
+       "Path('/Users/hamel/github/fastcore/fastcore')"
       ]
      },
-     "execution_count": null,
+     "execution_count": 60,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -1039,7 +1094,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 61,
    "metadata": {},
    "outputs": [
     {
@@ -1048,7 +1103,7 @@
        "Path('../fastcore')"
       ]
      },
-     "execution_count": null,
+     "execution_count": 61,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -1059,7 +1114,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 62,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1085,16 +1140,16 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 63,
    "metadata": {},
    "outputs": [
     {
      "data": {
       "text/plain": [
-       "Path('05_transform.ipynb')"
+       "Path('parallel_test.py')"
       ]
      },
-     "execution_count": null,
+     "execution_count": 63,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -1119,16 +1174,16 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 64,
    "metadata": {},
    "outputs": [
     {
      "data": {
       "text/plain": [
-       "(Path('../fastcore/all.py'), Path('05_transform.ipynb'))"
+       "(Path('../fastcore/shutil.py'), Path('parallel_win.ipynb'))"
       ]
      },
-     "execution_count": null,
+     "execution_count": 64,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -1144,7 +1199,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 65,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1157,7 +1212,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 66,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1180,7 +1235,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 67,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1193,7 +1248,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 68,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1217,7 +1272,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 69,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1230,7 +1285,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 70,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1262,7 +1317,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 71,
    "metadata": {},
    "outputs": [
     {
@@ -1304,7 +1359,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 72,
    "metadata": {},
    "outputs": [
     {
@@ -1313,7 +1368,7 @@
        "['e', 'd', 'c', 'b', 'a']"
       ]
      },
-     "execution_count": null,
+     "execution_count": 72,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -1332,7 +1387,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 73,
    "metadata": {},
    "outputs": [
     {
@@ -1358,7 +1413,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 74,
    "metadata": {},
    "outputs": [
     {
@@ -1367,7 +1422,7 @@
        "['e', 'd', 'c', 'b', 'a']"
       ]
      },
-     "execution_count": null,
+     "execution_count": 74,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -1387,7 +1442,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 75,
    "metadata": {},
    "outputs": [
     {
@@ -1396,7 +1451,7 @@
        "CacheInfo(hits=1, misses=1, maxsize=2, currsize=1)"
       ]
      },
-     "execution_count": null,
+     "execution_count": 75,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -1419,7 +1474,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 76,
    "metadata": {},
    "outputs": [
     {
@@ -1445,7 +1500,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 77,
    "metadata": {},
    "outputs": [
     {
@@ -1454,7 +1509,7 @@
        "CacheInfo(hits=0, misses=0, maxsize=2, currsize=0)"
       ]
      },
-     "execution_count": null,
+     "execution_count": 77,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -1471,7 +1526,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 78,
    "metadata": {},
    "outputs": [
     {
@@ -1504,16 +1559,16 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 79,
    "metadata": {},
    "outputs": [
     {
      "data": {
       "text/plain": [
-       "['h', 'b', 'e', 'g', 'a', 'd', 'f', 'c']"
+       "['b', 'f', 'h', 'a', 'g', 'c', 'e', 'd']"
       ]
      },
-     "execution_count": null,
+     "execution_count": 79,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -1526,7 +1581,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 80,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1546,7 +1601,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 81,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1565,7 +1620,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 82,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1608,7 +1663,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 83,
    "metadata": {},
    "outputs": [
     {
@@ -1617,7 +1672,7 @@
        "'https://github.com/fastai/fastcore/tree/master/fastcore/test.py#L34'"
       ]
      },
-     "execution_count": null,
+     "execution_count": 83,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -1638,7 +1693,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 84,
    "metadata": {},
    "outputs": [
     {
@@ -1647,7 +1702,7 @@
        "'nbformat/converter.py#L11'"
       ]
      },
-     "execution_count": null,
+     "execution_count": 84,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -1660,7 +1715,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 85,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1672,7 +1727,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 86,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1687,7 +1742,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 87,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1697,7 +1752,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 88,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1713,7 +1768,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 89,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1729,7 +1784,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 90,
    "metadata": {},
    "outputs": [
     {
@@ -1756,7 +1811,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 91,
    "metadata": {},
    "outputs": [
     {
@@ -1765,7 +1820,7 @@
        "'▂▅▇▇'"
       ]
      },
-     "execution_count": null,
+     "execution_count": 91,
      "metadata": {},
      "output_type": "execute_result"
     }
@@ -1776,7 +1831,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 92,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1793,7 +1848,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 93,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1807,7 +1862,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 94,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1821,7 +1876,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 95,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1835,7 +1890,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 96,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1859,7 +1914,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 97,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1871,7 +1926,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 98,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1899,7 +1954,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 99,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1913,7 +1968,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 100,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1934,7 +1989,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 101,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1951,7 +2006,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 102,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -1982,7 +2037,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 103,
    "metadata": {},
    "outputs": [
     {
@@ -2015,15 +2070,15 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 104,
    "metadata": {},
    "outputs": [
     {
      "name": "stdout",
      "output_type": "stream",
      "text": [
-      "Num Events: 7, Freq/sec: 315.8\n",
-      "Most recent:  ▇▁▁▂▅ 423.6 331.5 332.6 361.3 399.7\n"
+      "Num Events: 5, Freq/sec: 335.2\n",
+      "Most recent:  ▃▇▅▁▅ 295.5 381.6 305.9 192.9 313.0\n"
      ]
     }
    ],
@@ -2039,7 +2094,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 105,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -2049,7 +2104,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 106,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -2061,7 +2116,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 107,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -2071,7 +2126,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 108,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -2094,7 +2149,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 109,
    "metadata": {},
    "outputs": [
     {
@@ -2120,7 +2175,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 110,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -2141,7 +2196,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 111,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -2153,7 +2208,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 112,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -2165,14 +2220,14 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 113,
    "metadata": {},
    "outputs": [
     {
      "name": "stdout",
      "output_type": "stream",
      "text": [
-      "2000-01-01 12:00:00 UTC is 2000-01-01 22:00:00+10:00 local time\n"
+      "2000-01-01 12:00:00 UTC is 2000-01-01 04:00:00-08:00 local time\n"
      ]
     }
    ],
@@ -2183,7 +2238,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 114,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -2195,14 +2250,14 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 115,
    "metadata": {},
    "outputs": [
     {
      "name": "stdout",
      "output_type": "stream",
      "text": [
-      "2000-01-01 12:00:00 local is 2000-01-01 02:00:00+00:00 UTC time\n"
+      "2000-01-01 12:00:00 local is 2000-01-01 20:00:00+00:00 UTC time\n"
      ]
     }
    ],
@@ -2212,7 +2267,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 116,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -2244,7 +2299,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 117,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -2264,7 +2319,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 118,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -2283,7 +2338,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 119,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -2297,7 +2352,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 120,
    "metadata": {},
    "outputs": [
     {
@@ -2323,7 +2378,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 121,
    "metadata": {},
    "outputs": [],
    "source": [
@@ -2344,7 +2399,7 @@
   },
   {
    "cell_type": "code",
-   "execution_count": null,
+   "execution_count": 122,
    "metadata": {},
    "outputs": [
     {
@@ -2389,6 +2444,18 @@
    "display_name": "Python 3 (ipykernel)",
    "language": "python",
    "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.9.7"
   }
  },
  "nbformat": 4,
diff --git a/nbs/index.ipynb b/nbs/index.ipynb
index aae3de82..485dcad9 100644
--- a/nbs/index.ipynb
+++ b/nbs/index.ipynb
@@ -790,11 +790,23 @@
    "split_at_heading": true
   },
   "kernelspec": {
-   "display_name": "Python 3",
+   "display_name": "Python 3 (ipykernel)",
    "language": "python",
    "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.9.7"
   }
  },
  "nbformat": 4,
- "nbformat_minor": 2
+ "nbformat_minor": 4
 }