Is the time sheet a legal doc ? yes - in the sense that it can be used as evidence in a court case
if someone else fills it out -can you be made to sign it ? No just say I am not signing that ....
If the hours shown are the hours you worked - frankly I would sign
If they arent - I would not sign it on the grounds they are untrue
can they fill in the hours, when you've already previously done it....
so long as the hours are as you say, I would say yes
But what has really happened, I guess, is that there is a dispute about hours
and someone has said - these are your hours now sign it !
and if they arent I wouldnt.