Convert number of seconds since January 1, 1970 00:00:00 (epoch time) to a datetime format

I have a code that should convert number of seconds since January 1, 1970 00:00:00 (epoch time) to
a datetime format. It uses something like the following:

DateAdd("s",mydateinsecs,CreateDateTime(1970,1,1))

The problem is if the date is in DST (daylight savings time), 1 extra hour will be added to the resulting time by DateAdd().

Does someone how to fix it?