Time limit - -when does clock start running

[Chess Ref]

In our local SB beer leagues we have gametime as start time. If a game runs long the next start time is 5 minutes after end of previous game.

I have seen in our JO tourneys, time and it's application,evolve into very controversial stuff.
I personally have been reamed by more senior umps for starting a new inning when there was 2 minutes left. This was a 1 run game and quite frankly I was having a blast.
I have been uncomfortable when I am expected to lie/cheat people on the time stuff. I was BU when PU announced "Time has expired" and the losing team wanted another inning. The problem was the PU jerked them out of about 2 minutes. I just happened to keep time for myself that game and apparently so did the losing team. Big yelling, big protest. Finally UIC asked me if I had anything to add. . PU and some fellow umps pissed at me, some umps had my back, UIC not happy he asked me, assignor calls me at home and says.......good job-he's got my back........So my choices were back my partner who knowingly shorted them or tell what I had

bottom line for me is I go by the book ...no more no less.....