diff --git a/web/src/app/schedules/temp-sched/TempSchedAddShiftsStep.tsx b/web/src/app/schedules/temp-sched/TempSchedAddShiftsStep.tsx
index 0a80eb29db..c4e1f6f230 100644
--- a/web/src/app/schedules/temp-sched/TempSchedAddShiftsStep.tsx
+++ b/web/src/app/schedules/temp-sched/TempSchedAddShiftsStep.tsx
@@ -5,6 +5,9 @@ import {
   Grid,
   Typography,
   makeStyles,
+  FormControlLabel,
+  Checkbox,
+  FormHelperText,
 } from '@material-ui/core'
 import ArrowRightAltIcon from '@material-ui/icons/ArrowRightAlt'
 import { contentText, Shift, StepContainer } from './sharedUtils'
@@ -14,14 +17,23 @@ import TempSchedShiftsList from './TempSchedShiftsList'
 import TempSchedAddShiftForm from './TempSchedAddShiftForm'
 import { DateTime, Interval } from 'luxon'
 import { FieldError } from '../../util/errutil'
-import { isISOAfter } from '../../util/shifts'
+import { isISOAfter, parseInterval } from '../../util/shifts'
+import { Alert, AlertTitle } from '@material-ui/lab'
+import { useScheduleTZ } from './hooks'
+import { getCoverageGapItems } from './shiftsListUtil'
 
 const useStyles = makeStyles((theme) => ({
   contentText,
   avatar: {
     backgroundColor: theme.palette.primary.main,
   },
+  shiftsListContainer: {
+    height: '100%',
+    display: 'flex',
+    flexDirection: 'column',
+  },
   listOuterContainer: {
+    height: '100%',
     position: 'relative',
     overflowY: 'auto',
   },
@@ -36,6 +48,10 @@ const useStyles = makeStyles((theme) => ({
     maxHeight: '100%',
     paddingRight: '2rem',
   },
+  noCoverageError: {
+    marginTop: '.5rem',
+    marginBottom: '.5rem',
+  },
 }))
 
 type AddShiftsStepProps = {
@@ -46,6 +62,10 @@ type AddShiftsStepProps = {
 
   scheduleID: string
   edit?: boolean
+
+  coverageGapsAllowed?: boolean
+  setCoverageGapsAllowed: (isAllowed: boolean) => void
+  isShowingCoverageGapsWarning: boolean
 }
 
 type DTShift = {
@@ -102,10 +122,14 @@ export default function TempSchedAddShiftsStep({
   end,
   value,
   edit,
+  coverageGapsAllowed,
+  setCoverageGapsAllowed,
+  isShowingCoverageGapsWarning,
 }: AddShiftsStepProps): JSX.Element {
   const classes = useStyles()
   const [shift, setShift] = useState(null as Shift | null)
   const [submitted, setSubmitted] = useState(false)
+  const { zone, q } = useScheduleTZ(scheduleID)
 
   // set start equal to the temporary schedule's start
   // can't this do on mount since the step renderer puts everyone on the DOM at once
@@ -160,6 +184,12 @@ export default function TempSchedAddShiftsStep({
     setSubmitted(false)
   }
 
+  const hasCoverageGaps = (() => {
+    if (q.loading) return false
+    const schedInterval = parseInterval({ start: start, end: end }, zone)
+    return getCoverageGapItems(schedInterval, value, zone).length > 0
+  })()
+
   return (
     <StepContainer data-cy='add-shifts-step'>
       {/* main container for fields | button | shifts */}
@@ -211,20 +241,44 @@ export default function TempSchedAddShiftsStep({
         </Grid>
 
         {/* shifts list container */}
-        <Grid item xs={6} className={classes.listOuterContainer}>
-          <div className={classes.listInnerContainer}>
-            <TempSchedShiftsList
-              scheduleID={scheduleID}
-              value={value}
-              start={start}
-              end={end}
-              onRemove={(shift: Shift) => {
-                setShift(shift)
-                onChange(value.filter((s) => !shiftEquals(shift, s)))
-              }}
-              edit={edit}
-            />
+        <Grid item xs={6} className={classes.shiftsListContainer}>
+          <div className={classes.listOuterContainer}>
+            <div className={classes.listInnerContainer}>
+              <TempSchedShiftsList
+                scheduleID={scheduleID}
+                value={value}
+                start={start}
+                end={end}
+                onRemove={(shift: Shift) => {
+                  setShift(shift)
+                  onChange(value.filter((s) => !shiftEquals(shift, s)))
+                }}
+                edit={edit}
+              />
+            </div>
           </div>
+          {isShowingCoverageGapsWarning && hasCoverageGaps && (
+            <Alert severity='error' className={classes.noCoverageError}>
+              <AlertTitle>Gaps in coverage</AlertTitle>
+              <FormHelperText>
+                There are gaps in coverage. During these gaps, nobody on the
+                schedule will receive alerts. If you still want to proceed,
+                check the box and retry.
+              </FormHelperText>
+              <FormControlLabel
+                label='Allow gaps in coverage'
+                labelPlacement='end'
+                control={
+                  <Checkbox
+                    data-cy='no-coverage-checkbox'
+                    checked={coverageGapsAllowed}
+                    onChange={(e) => setCoverageGapsAllowed(e.target.checked)}
+                    name='allowCoverageGaps'
+                  />
+                }
+              />
+            </Alert>
+          )}
         </Grid>
       </Grid>
     </StepContainer>
diff --git a/web/src/app/schedules/temp-sched/TempSchedDialog.tsx b/web/src/app/schedules/temp-sched/TempSchedDialog.tsx
index 2b34900608..430170d0c5 100644
--- a/web/src/app/schedules/temp-sched/TempSchedDialog.tsx
+++ b/web/src/app/schedules/temp-sched/TempSchedDialog.tsx
@@ -13,6 +13,7 @@ import { parseInterval } from '../../util/shifts'
 import { DateTime } from 'luxon'
 import { getNextWeekday } from '../../util/luxon-helpers'
 import { useScheduleTZ } from './hooks'
+import { getCoverageGapItems } from './shiftsListUtil'
 // allows changing the index programatically
 const VirtualizeAnimatedViews = virtualize(SwipeableViews)
 
@@ -85,6 +86,28 @@ export default function TempSchedDialog({
     },
   })
 
+  const [shouldAllowNoCoverage, setShouldAllowNoCoverage] = useState(false)
+  const [isShowingCoverageGapsWarning, setIsShowingCoverageGapsWarning] =
+    useState(false)
+
+  const hasCoverageGaps = (() => {
+    if (q.loading) return false
+    const schedInterval = parseInterval(value, zone)
+    return getCoverageGapItems(schedInterval, value.shifts, zone).length > 0
+  })()
+
+  const handleSubmit = (): void => {
+    if (hasCoverageGaps && !shouldAllowNoCoverage) {
+      setIsShowingCoverageGapsWarning(true)
+      return
+    }
+    if (isShowingCoverageGapsWarning && shouldAllowNoCoverage) {
+      setIsShowingCoverageGapsWarning(false)
+    }
+
+    submit()
+  }
+
   type SlideRenderer = {
     index: number
     key: number
@@ -111,6 +134,9 @@ export default function TempSchedDialog({
           start={value.start}
           end={value.end}
           edit={edit}
+          coverageGapsAllowed={shouldAllowNoCoverage}
+          setCoverageGapsAllowed={setShouldAllowNoCoverage}
+          isShowingCoverageGapsWarning={isShowingCoverageGapsWarning}
         />
       )
     }
@@ -119,13 +145,20 @@ export default function TempSchedDialog({
     return <div />
   }
 
+  const noCoverageErrs =
+    hasCoverageGaps && isShowingCoverageGapsWarning
+      ? [new Error('This temporary schedule has gaps in coverage.')]
+      : []
   const nonFieldErrs = nonFieldErrors(error).map((e) => ({
     message: e.message,
   }))
   const fieldErrs = fieldErrors(error).map((e) => ({
     message: `${e.field}: ${e.message}`,
   }))
-  const errs = nonFieldErrs.concat(fieldErrs).concat(shiftErrors)
+  const errs = nonFieldErrs
+    .concat(fieldErrs)
+    .concat(shiftErrors)
+    .concat(noCoverageErrs)
 
   return (
     <FormDialog
@@ -174,7 +207,7 @@ export default function TempSchedDialog({
           />
         </FormContainer>
       }
-      onSubmit={() => submit()}
+      onSubmit={handleSubmit}
       onNext={step === 1 ? null : () => setStep(step + 1)}
       onBack={(edit ? step === 1 : step === 0) ? null : () => setStep(step - 1)}
     />
diff --git a/web/src/cypress/integration/temporarySchedule.ts b/web/src/cypress/integration/temporarySchedule.ts
index 23d66528a7..2c00b6e94d 100644
--- a/web/src/cypress/integration/temporarySchedule.ts
+++ b/web/src/cypress/integration/temporarySchedule.ts
@@ -118,11 +118,14 @@ function testTemporarySchedule(screen: string): void {
     )
     cy.get('[data-cy="loading-button"]').contains('Next').click()
     cy.get(addShiftsSelector).should('be.visible.and.contain', 'STEP 2 OF 2')
+    cy.get('[data-cy="no-coverage-checkbox"]').should('not.exist')
     cy.dialogForm({ userID: manualAddUser.name }, addShiftsSelector)
     cy.get('[data-cy="shifts-list"]').should('not.contain', manualAddUser.name)
     cy.get('button[data-cy="add-shift"]').click()
     cy.get('[data-cy="shifts-list"]').should('contain', manualAddUser.name)
-    cy.dialogFinish('Submit')
+    cy.get('[data-cy="loading-button"]').contains('Submit').click()
+    cy.get('[data-cy="no-coverage-checkbox"]').should('be.visible').click()
+    cy.dialogFinish('Retry')
     cy.visit('/schedules/' + schedule.id + '?start=' + start.toISO())
     cy.get('div').contains('Temporary Schedule').click()
     cy.get('div[data-cy="shift-tooltip"]').should('be.visible')
@@ -167,7 +170,9 @@ function testTemporarySchedule(screen: string): void {
       )
       cy.get('button[data-cy="add-shift"]').click()
       cy.get('[data-cy="shifts-list"]').should('contain', manualAddUser.name)
-      cy.dialogFinish('Submit')
+      cy.get('[data-cy="loading-button"]').contains('Submit').click()
+      cy.get('[data-cy="no-coverage-checkbox"]').should('be.visible').click()
+      cy.dialogFinish('Retry')
       cy.reload() // ensure calendar update
       cy.get('div').contains(manualAddUser.name).click()
       cy.get('div[data-cy="shift-tooltip"]').should('be.visible')