Ruby

It is not good idea to restrict current methods to reject invalid dates and times.

I tried to verify invalid time using round trip test once.
(ruby-core:14517, ruby-dev:33058, r14765, r15203)

But it caused bigger problems over benefits.

Invalid date/time is difficult to determine.
It is almost impossible by application because it depends various factors:
Month, leap year, summer time, leap seconds, time zone definition change.

Sometimes application needs a Time object near given year/month/day/hour/minute/second.
It is very difficult to do using the restricted methods.

So, methods only accept valid dates are less useful than current methods.

Patch to the above bug :

class SmartTime < Time def self.mktime year, month, day case month when 4, 6, 9, 11 if day == 31 raise ArgumentError, 'argument out of range _ APR, JUNE, SEP, NOV', caller else super end when 2 case day when 30, 31 raise ArgumentError, 'argument out of range _ FEB', caller when 29 if year%100 == 0 if year%400 == 0 super else raise ArgumentError, 'argument out of range _ FEB', caller end else if year%4 == 0 super else raise ArgumentError, 'argument out of range _ FEB', caller end end else super end else super end end end