[wp-trac] [WordPress Trac] #34435: get_gmt_from_date() can return incorrect value when input during fall's DST switch

[WordPress Trac]

#34435: get_gmt_from_date() can return incorrect value when input during fall's DST
switch
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 Reporter:  danielbachhuber         |       Owner:
     Type:  defect (bug)            |      Status:  new
 Priority:  normal                  |   Milestone:  Future Release
Component:  Date/Time               |     Version:
 Severity:  normal                  |  Resolution:
 Keywords:  needs-patch needs-docs  |     Focuses:
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Comment (by Rarst):

 Replying to [comment:2 danielbachhuber]:
 > After talking this through time and time again, @viper007bond and I feel
 reasonably confident that DST should be abolished.
 >
 > The bug is most likely that 1:23 am occurs twice in London on
 2015-10-25. `DateTime` doesn't know how to distinguish between them when
 doing relative time conversions so it assumes the later one. It could pick
 the correct one if it knew the UTC time.

 To be more precise what happens isn't just random assumption. PHP has a
 registered transition for `Europe/London` from BST to GMT at
 `2015-10-25T01:00:00+0000`. So I think  input before `01:00` is considered
 still in BST and after `01:00` is considered in GMT.

 And yeah, on WP side it should ideally all just operate in UTC as much as
 possible. Concept of a "local" time for a post is deeply broken in many
 places.

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Ticket URL: <https://core.trac.wordpress.org/ticket/34435#comment:7>
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