Date/Time perl modules

• Date::Manip - Big. Needs several step sto convert to/from eopch seconds. But you could just subtract 1 week's worth of seconds.
• Date::Calc - Less big, simpler. Has Add_Delta_Days. Doesn't generate BST from epoch seconds (on Mac).
• POSIX - has strftime. Can easily generate epoch seconds from the current time. Lacking in conversion to date?
• DateTime - The best and easiest.