Package “dateutils” has 11 man pages.

Add DURATION to DATE/TIME and print the result. If DATE/TIME is omitted but DURATION is given, read a list of DATE/TIMEs from stdin. If DURATION is omitted but...
Convert DATE/TIMEs between calendrical systems. If DATE/TIME is omitted date/times are read from stdin.
Compute duration from DATE/TIME (the reference date/time) to the other DATE/TIMEs given and print the result as duration. If the other DATE/TIMEs are omitted...
Grep standard input for lines that match EXPRESSION. EXPRESSION may be date/times prefixed with an operator `<', `<=', `=', `>=', `>', `!=', `<>' (if omitted...
Round DATE/TIME to the next occurrence of RNDSPEC. If DATE/TIME is omitted a stream of date/times is read from stdin. DATE/TIME can also be one of the following...
Generate a sequence of date/times from FIRST to LAST, optionally in steps of INCREMENT (which defaults to `1d'). If LAST is omitted it defaults to `now' if...
Sort contents of FILE chronologically. If FILE is omitted read from stdin. The first date/time value per line is the sort key. Dates without times account for a...
Like test(1) but for dates.
dateutils are a bunch of tools that revolve around fiddling with dates and times in the command line with a strong focus on use cases that arise when dealing...
Convert DATE/TIMEs between timezones. If DATE/TIME is omitted, it defaults to `now'.
Parse input from stdin according to one of the given formats FORMATs. The format string specifiers are the same as for strptime(3).