Question

Given 3 numbers: DD, MM, YYYY, what is the easiest way to know if they combine a legal date ?

Examples:

14, 05, 2011     =>     Legal
29, 02, 2011     =>     Illegal
29, 02, 2012     =>     Legal
35, 11, 1989     =>     Illegal
14, 18, 2011     =>     Illegal
14, 00, 2011     =>     Illegal
00, 11, 1979     =>     Illegal
31, 11, 1979     =>     Illegal

Answer 1

You can use valid_date? But it’s YYYY, MM, DD:

irb(main):015:0> require 'date'
=> true
irb(main):021:0> Date::valid_date?(2011,05,14)
=> true
irb(main):022:0> Date::valid_date?(2011,02,29)
=> false
irb(main):023:0> Date::valid_date?(2012,02,29)
=> true