Assuming you want to track the number of hours spent on the thing, can you do something with tracking the hours you spend on OTHER activities? I guess you’d need to do that in a do-less goal, with the rate and starting buffer set so that you could enter 24 hours for the first few days until the first weekend arrives.
waves hands vaguely
If I were doing it, I’d create a do-more goal with a zero rate for recording the time spent on the actual thing and then do something with integromat / ifttt / etc to automatically copy the data to the do-less goal.