If I recall correctly, the time starts the same time the opening cutscene does, so I think the time would be 0. Of course, I've yet to test this.

Ok, let's say it's possible in the game programmatically (the value is stored as signed, not unsigned).

The only way I see to accomplish it, is to modify the value directly in memory.

If the time is counted in seconds directly and computed to points, I think it's safe to assume that the calculated score would be negative.

In the case that there's still a manipulation to/from minutes, there's a quirk if the modulo % operator is used. In that case it becomes tricky for negative values: a%b for a<0.

i think i know how
There are programs like Cheat Engine that can change the value of numeric codes, etc., but it can be complicated, but if we pause it in a second of a level and then in another amount of another level.
example: I end in one level with 0:50 and in another at 1:25 and we change it in another to -0:02
that's my theory