bug#37961: Bug report of date commond

[Paul Eggert]

On 10/28/19 12:34 AM, zhangzhi...@mail.iap.ac.cn wrote:

~>date  -d "1940-06-01" +"%Y-%m-%d"
date: invalid date ‘1940-06-01’


Presumably your TZ setting is Asia/Shanghai, as I see the symptoms as 
follows:


$ TZ=Asia/Shanghai date  -d "1940-06-01" +"%Y-%m-%d"
date: invalid date ‘1940-06-01’

This is because there is no instant of time 1940-06-01 00:00:00 in 
Shanghai, as the the clock ticked over from 1940-05-30 23:59:59 to 
1940-06-01 01:00:00 due to a daylight-saving time transition.


For this particular case, you'll have better luck with:

$ date -d "1940-06-01 12:00" +"%Y-%m-%d"

but this sort of approach does not work in general, because 12:00 does 
not always exist either. In other words, the 'date' command is not 
suited for calendrical arithmetic in general, only for time arithmetic.

bug#37961: Bug report of date commond

[zhangzhi...@mail.iap.ac.cn]

Mr. maintainers:
Hello! I am very glad to write this email to report my problem.
When I am running commond on my server： 

~>date  -d "1940-06-01" +"%Y-%m-%d"
date: invalid date ‘1940-06-01’

but the other commond works right：
sense3:~>date  -d '1939-06-01' +"%Y-%m-%d"
1939-06-01
sense3:~>date  -d '1940-06-02' +"%Y-%m-%d"
1940-06-02
sense3:~>date  -d '1940-05-31' +"%Y-%m-%d"
1940-05-31
sense3:~>date  -d '1940-07-02' +"%Y-%m-%d"
1940-07-02
sense3:~>date  -d '1940-07-01' +"%Y-%m-%d"
1940-07-01
sense3:~>date  -d '1940-05-01' +"%Y-%m-%d"
1940-05-01


my server's version and date version is：
~>uname -a
Linux zenglab 3.10.0-957.12.1.el7.x86_64 #1 SMP Mon Apr 29 14:59:59 UTC 2019 
x86_64 x86_64 x86_64 GNU/Linux
~>date --version
date (GNU coreutils) 8.22
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later .
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Written by David MacKenzie.

This error makes my program woking wrong. Hope for your reply.

Thank you!






 张志敏 技术工程师
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