seconds - convert human-readable date (and time) to seconds since epoch seconds date ... Seconds prints the number of seconds since 1 Jan 1970 corresponding to one or more human-readable date s. Each date must be one argument; it will usually be necessary to enclose it in quotes.

Seconds accepts a somewhat wider range of input than just output from date (1). The main requirement is that the date must be fully specified, with a day of month, month and year in any order. The month must be an English name (or abbreviation), not a number, and the year must contain 4 digits. Unambiguous time-zone names are understood (i.e., not .LR IST ) or time zones may be written as ±hhmm . Case is ignored.

Print the names of all files under .L . modified since the start of 23 May 2011. .EX du -ta | awk '$1 >= '^`{seconds '23 may 2011'}^' {print $2}' date (1), du (1), mtime (1), ctime (2) All-numeric dates, popular in the USA, are simply ambiguous, more so if the year is truncated to 2 digits.