Hello!

I'm having trouble applying a formula (I tried the formulas listed here) to two columns, one column with the date and another with the time. Specifically, I'm trying to adjust the date AND time listed in two columns into a single column with the adjusted times, GMT to California time PST (GMT).
Is there an adjustment I can work into the formula to adjust the date as well?

I had some success with this formula:
(the times were in column F, and this was row 2)
=F:F F2 - TIME(7, 0, 0)

However, when the times were adjusted beyond a certain point, I had ##### in my data due to the date also needing to be adjusted.
If the date column was "E", what would that formula look like?

Any thoughts?
Many thanks in advance.