timestamp and timezone

Hello,

I have some date and time stored in the db. Everything is saved as "varchar(10) NOT NULL default '0'," as timestamp. The normal Contao way of datetime.

We know that in Contao backend you can set the timezone your using.

Question 1 :
Now, when I what to use a timestamp, should I correct-it with the timezone by myself? (normally yes)

Question 2 :
Is there a best practice (I mean the Léo way ;-) )

Question 3 :
Is this different if you are in frontend, backend or extends Backend, Module...

Thanks

Every date or time can be parsed two ways: either via parseDate() function or by a Date class. I am not sure if they consider timezone, but you could check that really fast:
/system/libraries/Date.php
/system/libraries/System.php (line 391)
I don't see there any reference to timezone though.