Bug #15340
closedTime.local behaving inconsistently for excess days after 2038
Description
Time.local accepts a day of month that exceeds the largest day of the month, for example, 2018-02-31. The behavior looks inconsistent before v.s. after 2038. Are they expected behavior?
The behavior looks somewhat reasonable before 2037. The number of exceeding days is passed on the next month. 2018-02-31 exceeds for 3 days since 2018-02-28. 2018-02-31 is recognized as 2018-03-03.
But after 2038, the behavior looks strange and inconsistent compared to before 2038, as shown in the example below observed in Ruby 2.4.1 and 2.5.1.
The difference looks affecting Time.strptime as well.
irb(main):001:0> ENV['TZ']=nil
=> nil
irb(main):002:0> Time.local(2037,2,28,0,0,0,0)
=> 2037-02-28 00:00:00 +0900
irb(main):003:0> Time.local(2037,2,29,0,0,0,0)
=> 2037-03-01 00:00:00 +0900
irb(main):004:0> Time.local(2037,2,30,0,0,0,0)
=> 2037-03-02 00:00:00 +0900
irb(main):005:0> Time.local(2037,2,31,0,0,0,0)
=> 2037-03-03 00:00:00 +0900
irb(main):006:0> Time.local(2038,2,28,0,0,0,0)
=> 2038-02-28 00:00:00 +0900
irb(main):007:0> Time.local(2038,2,29,0,0,0,0)
=> 2038-03-01 00:00:00 +0900
irb(main):008:0> Time.local(2038,2,30,0,0,0,0)
=> 2038-02-28 00:00:00 +0900
irb(main):009:0> Time.local(2038,2,31,0,0,0,0)
=> 2038-03-01 00:00:00 +0900
irb(main):010:0> ENV['TZ']='UTC'
=> "UTC"
irb(main):011:0> Time.local(2037,2,28,0,0,0,0)
=> 2037-02-28 00:00:00 +0000
irb(main):012:0> Time.local(2037,2,29,0,0,0,0)
=> 2037-03-01 00:00:00 +0000
irb(main):013:0> Time.local(2037,2,30,0,0,0,0)
=> 2037-03-02 00:00:00 +0000
irb(main):014:0> Time.local(2037,2,31,0,0,0,0)
=> 2037-03-03 00:00:00 +0000
irb(main):015:0> Time.local(2038,2,28,0,0,0,0)
=> 2038-02-28 00:00:00 +0000
irb(main):016:0> Time.local(2038,2,29,0,0,0,0)
=> 2038-03-01 00:00:00 +0000
irb(main):017:0> Time.local(2038,2,30,0,0,0,0)
=> 2038-02-28 00:00:00 +0000
irb(main):018:0> Time.local(2038,2,31,0,0,0,0)
=> 2038-03-01 00:00:00 +0000
JFYI: I thought I observed a case 2038-02-30 is recognized as 2038-03-01 when ENV['TZ']=nil, but just now I couldn't reproduce the case. It might be my mistake in operations, but let me leave the log just in case. (It might be because I was in different timezones when I observed them. The example above was in JST, and the below was in PST.)
irb(main):001:0> ENV['TZ']=nil
=> nil
irb(main):002:0> Time.local(2037,2,30,0,0,0,0)
=> 2037-03-02 00:00:00 -0800
irb(main):003:0> Time.local(2038,2,30,0,0,0,0)
=> 2038-03-01 00:00:00 -0800
Updated by naruse (Yui NARUSE) almost 6 years ago
I thought I observed a case 2038-02-30 is recognized as 2038-03-01 when ENV['TZ']=nil, but just now I couldn't reproduce the case. It might be my mistake in operations, but let me leave the log just in case. (It might be because I was in different timezones when I observed them. The example above was in JST, and the below was in PST.)
ENV['TZ'] = nil
means "Use system default timezone". In other words, it means Asia/Tokyo
in Japan, and America/Los_Angeles
in West America.
Updated by naruse (Yui NARUSE) almost 6 years ago
- Status changed from Open to Closed
Applied in changeset trunk|r65974.
Normalize month-mday before finding epoch
Especially over the year 2038, 30 Feb and so on may cause odd behavior
on validating found epoch with given year-month-day [Bug #15340]
Updated by naruse (Yui NARUSE) almost 6 years ago
- Backport changed from 2.3: UNKNOWN, 2.4: UNKNOWN, 2.5: UNKNOWN to 2.3: WONTFIX, 2.4: REQUIRED, 2.5: REQUIRED
Updated by nagachika (Tomoyuki Chikanaga) almost 6 years ago
- Backport changed from 2.3: WONTFIX, 2.4: REQUIRED, 2.5: REQUIRED to 2.3: WONTFIX, 2.4: REQUIRED, 2.5: DONE
ruby_2_5 r66839 merged revision(s) 65974.
Updated by usa (Usaku NAKAMURA) almost 6 years ago
- Backport changed from 2.3: WONTFIX, 2.4: REQUIRED, 2.5: DONE to 2.3: WONTFIX, 2.4: DONE, 2.5: DONE
ruby_2_4 r66967 merged revision(s) 65974.