Question

from 8:58 to 12:30 how many hours did i work

Answer 1

you worked 5hrs & 2mins. approximately ?

Answer 2

From 8:58 to 9:00, there is 2 minutes.
From 9:00 to 12:00 there is 3 hours. 
From 12:00 to 12:30 there is 30 minutes. 
So therefore you worked 3 hours and 32 minutes. Technically, you can round it to closer to 4 hours.