60 seconds and 1 minute aren't really the same?

this is a bit of random question, but the answer has been budding me for a long time. OK so.. On a macrowave, if you push 60, then it will cook for 60 seconds or one minute. (following me?) AND>>> if you also press 1;00 it will cook for on eminute, or 60 seconds, (Right,right?) OK?!?! well, my... show more this is a bit of random question, but the answer has been budding me for a long time. OK so..

On a macrowave, if you push 60, then it will cook for 60 seconds or one minute.
(following me?)
AND>>> if you also press 1;00 it will cook for on eminute, or 60 seconds, (Right,right?)
OK?!?! well, my question is....

if you add 1:00 + 1:00 it is = 2:00 right? So your food will cook for a total of two minutes.

BUT if you add 60 seconds + 60 seconds it will only cook for one minute and twnty seconds. Even though 60 seconds is one minute

I guess to put it into simpliest term, How come 1 minute + 1 minute equal 2 minutes in the thing of the macrowade, but 60 seconds + 60 seconds equal only one minute and twenty seconds?
Update: Gawd dammint a minute and 20 seconds. Not 120 seconds
Update 2: You terd can't read