YOU MIGHT NOT NEED DATE-FNS

Generic Helpers

format
formatDistance
formatDistanceStrict
formatDistanceToNow
formatDistanceToNowStrict
formatISO
formatISO9075
formatISODuration
formatRFC3339
formatRFC7231
formatRelative
intervalToDuration
lightFormat
parse
parseISO
parseJSON
set
sub
toDate

Interval Helpers

eachMonthOfInterval
eachWeekOfInterval
eachWeekendOfInterval
eachYearOfInterval
getOverlappingDaysInIntervals

Day Helpers

addBusinessDays
differenceInBusinessDays
differenceInCalendarDays
endOfDay
endOfTomorrow
endOfYesterday
setDayOfYear
startOfDay
startOfToday
startOfTomorrow
startOfYesterday
subBusinessDays

Weekday Helpers

setDay
setISODay

Week Helpers

addWeeks
differenceInCalendarWeeks
differenceInWeeks
endOfWeek
getWeek
getWeekOfMonth
getWeeksInMonth
isSameWeek
isThisWeek
lastDayOfWeek
setWeek
startOfWeek
subWeeks

ISO Week Helpers

differenceInCalendarISOWeeks
endOfISOWeek
getISOWeek
isSameISOWeek
isThisISOWeek
lastDayOfISOWeek
setISOWeek
startOfISOWeek

Month Helpers

differenceInCalendarMonths
differenceInMonths
eachWeekendOfMonth
endOfMonth
getDaysInMonth
startOfMonth

Quarter Helpers

addQuarters
differenceInCalendarQuarters
differenceInQuarters
endOfQuarter
getQuarter
isSameQuarter
isThisQuarter
lastDayOfQuarter
setQuarter
startOfQuarter
subQuarters

Year Helpers

eachWeekendOfYear
endOfYear
getDaysInYear
lastDayOfYear
startOfYear
subYears

ISO Week-Numbering Year Helpers

addISOWeekYears
differenceInCalendarISOWeekYears
differenceInISOWeekYears
endOfISOWeekYear
getISOWeekYear
getISOWeeksInYear
isSameISOWeekYear
lastDayOfISOWeekYear
setISOWeekYear
startOfISOWeekYear
subISOWeekYears

Decade Helpers

endOfDecade
getDecade
lastDayOfDecade
startOfDecade

Week-Numbering Year Helpers

getWeekYear
setWeekYear
startOfWeekYear