Question

I have set my server s timezone to be UTC. My users can select their own timezones like UTC+2 etc. I have created a query to indicate when a shift is open or closed:

SELECT DAYNAME(NOW()), start_day
FROM Shifts
WHERE (start_day = LOWER(DAYNAME(NOW()))
       AND start_time < CURTIME()
       AND end_time > CURTIME())
   OR (start_day = LOWER(DAYNAME(DATE_SUB(NOW(), INTERVAL 1 DAY)))
       AND start_time < ADDTIME('24:00:00', CURTIME())
       AND end_time > ADDTIME('24:00:00', CURTIME()))

I want to alter this query, NOW() and CURTIME() to match the settings of each user. How should I alter my query, to inject custom UTC in it? Is there another way to accomplish what I need ?

Answer 1

CONVERT_TZ function will solve your problem.

• Syntax

  CONVERT_TZ(dt, from_tz, to_tz).

  “from_tz” is your server timezone (in your case , UTC).

  “to_tz” value can be given as a string indicating an offset from “from_tz”, such as ‘+10:00’ or ‘-6:00’.

• Examples:

   SELECT CONVERT_TZ('2004-01-01 12:00:00','UTC','+2:00');
   SELECT CONVERT_TZ(NOW(), 'UTC', '-5:30');
   SELECT CONVERT_TZ(NOW(), '-2:00', '+5:00')