Why date() works twice as fast if we set time zone from code?

Question

Have you noticed that date() function works 2x faster than usual if you set actual timezone inside your script before any date() c

Answer 1

I'd imagine it has to determine the timezone for itself each time it's called unless explicitly specified, which adds to the function runtime.

But really, does it matter? How many scripts are you likely to make that call date() 100,000 times per run?