diff --git a/packages/date/README.md b/packages/date/README.md
index 2fc621c6fc4117..d5e0792395849d 100644
--- a/packages/date/README.md
+++ b/packages/date/README.md
@@ -117,7 +117,7 @@ _Parameters_
 
 -   _from_ `Moment | Date | string | undefined`: The timestamp to measure from. Defaults to the current time if undefined or invalid.
 -   _to_ `Moment | Date | string | undefined`: The timestamp to measure to. Defaults to the current time if undefined or invalid.
--   _includeAffix_ `boolean`: Whether to include the "ago" suffix in the comparison.
+-   _includeAffix_ `boolean`: Whether to include the "ago" or "to" affix in the comparison.
 
 _Returns_
 
diff --git a/packages/date/src/index.js b/packages/date/src/index.js
index 3cf500c37cd80e..c0fe4705c5ff9c 100644
--- a/packages/date/src/index.js
+++ b/packages/date/src/index.js
@@ -565,10 +565,11 @@ export function getDate( dateString ) {
  *
  * @param {Moment | Date | string | undefined} from         The timestamp to measure from. Defaults to the current time if undefined or invalid.
  * @param {Moment | Date | string | undefined} to           The timestamp to measure to. Defaults to the current time if undefined or invalid.
- * @param {boolean}                            includeAffix Whether to include the "ago" suffix in the comparison.
+ * @param {boolean}                            includeAffix Whether to include the "ago" or "to" affix in the comparison.
  * @return {string} The difference between the timestamps.
  */
 export function humanTimeDiff( from, to, includeAffix ) {
+	// Normalize inputs to a moment object, defaults to current time.
 	from = momentLib( from );
 	to = momentLib( to );
 	return from.from( to, ! includeAffix );