Bug #10588: Invalid Dates

• Status: Rejected
• Assignee: akr (Akira Tanaka)
• Target version: -
• ruby -v: 2.0.0-p481
• Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN

[NorthernLights (Imran "")]

I was in the process of implementing a date-routine, which could prevent possible out-of-range/invalid date values.

The interpreter, rightfully, threw an out-of range error, when I tried any of the following:
puts Time.mktime 2014, 13, 32
puts Time.mktime 2014, 13, 32

No surprises there. However, when I tried:
puts Time.mktime 2014, 11, 31
The interpreter, happily produced: 2014-12-01.

A little intrigued, I went ahead and tried the following routine:
1.upto(12){|month| puts Time.mktime 2014, month, 31}

Result:
2014-01-31 ok
2014-03-03 ???
2014-03-31 ok
2014-05-01 ???
2014-05-31 ok
2014-07-01 ???
2014-07-31 ok
2014-08-31 ok
2014-10-01 ???
2014-10-31 ok
2014-12-01 ???
2014-12-31 ok

I hope, I've been able to describe this issue adequately.

Thanks Matz & all the contributors for bringing this wonderful tool to us.

Regards.

[akr (Akira Tanaka)]

• Status changed from Open to Rejected

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.

[akr (Akira Tanaka)]

• Related to Feature #9549: Improvements to Time::strptime added

[akr (Akira Tanaka)]

• Has duplicate Bug #10703: Invalid Dates Bug Patch added

[NorthernLights (Imran "")]

• File SmartTime.rb SmartTime.rb added

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

[akr (Akira Tanaka)]

• Related to Bug #10767: Time.local doesn't raise an exception during the dead hour on DST added

[akr (Akira Tanaka)]

• Assignee set to akr (Akira Tanaka)