if the server/client/db where all always in the same timezone
then there is no problem and you can switch just fine.
problem is if the client was in CEST and a server was UTC
then when the property is false the client would insert let say “13:00”
the server would convert this and insert “11:00” in the db (utc is 2 hours earlier in this example)
a client would just get 13:00 back, other clients that are in the server UTC zone would get 11:00 back with this setting…
If you had this property to true then the “13:00” of the client would come to the server as “11:00” we convert it to “13:00” and insert it like that, and any other clients in what kind of time zone they are will also get “13:00” back. (because of the conversion the other way) So now it is always table. You insert “13:00” and where ever you are you get “13:00” back. No matter where the server is in or where clients are in.
but if you have the false situation first so “13:00” at the client “11:00” at the server (and ‘in’ the db)
then for that client if you switch that client suddenly will get “11:00” back for that time… because you always get exactly what the server gets. (there is a conversion done only 1 way now, not both for that value)
So that client sees the same value now that another client also sees which is in the same timezone as the server.