Detect if a date is in Daylight saving time in MySql

Question

I have inherited a legacy application where all the dates and times are stored in the local timezone (UK). I am not in a position to change how these are stored.

Howeve

Answer 1

Timezones are not stored in DATETIME values. Interestingly, they are for TIMESTAMPs.

Given a stored date, you can posthumously figure out if DST was "on" at that time based on the local rules. Since you can't change the dates, I would guess that you can't add a column to store the timezone...

Make a stored procedure that contains the rules and converts a given date to GMT.

Note that only the people that live around Greenwich want their times displayed in GMT. :)

Good luck.