Core modules

• Time::Piece
  • Time::Seconds
• Time::Local
• Time::HiRes
• POSIX
  • POSIX::asctime() — converts broken-down time into a string
  • POSIX::ctime() — converts a Unix timestamp into a string
  • POSIX::mktime() — converts broken-down time into a Unix timestamp (i.e. what Time::Local does)
  • POSIX::strftime() — converts broken-down time into a string, using a format string
  • POSIX::tzname()
  • POSIX::tzset()
  • Time::Piece->strptime() — parses a string into a Time::Piece object, using a format string

Important modules

• DateTime
• Date::Manip
• Date::Format, Date::Parse
• Date::Simple

Parsing

• high-level
  • HTTP::Date
  • Date::Parse
  • Time::ParseDate
  • DateTime::Format::Natural
  • Date::Manip -- parse()
• medium-level
  • Time::Piece->strptime() [man page]
• low-level
  • Time::Local
  • POSIX::mktime()

If you're stuck using low-level parsing libraries, here is some useful information for writing custom date parsers.

Timezones

• $ENV{TZ} (list)
• DateTime::TimeZone
• Date::Manip::Zones
• POSIX::tzname()
• POSIX::tzset()

To change your script's local timezone at the top of the script:

use POSIX;

$ENV{TZ} = 'CST6CDT';
POSIX::tzset();

Formatting

• strftime() is the quintessential function here, and can be found in various places:
  • POSIX::strftime()
  • DateTime->strftime()
  • Date::Format
• rounding to English expressions (eg. "6 seconds ago", "4 days ago")
  • Time::Duration
  • DateTimeX::Format::Ago
  • DateTime::Format::Human::Duration