It's Friday, so it's worth remembering that *even if* you work for yourself, but especially if you sell your labor to someone else, that you are under no obligation to do more than your job description nor work for more hours than you are contracted to.
If you *want* to do extra things or extra hours, you should receive actual compensation for it in the form of increased pay, overtime, or time-in-lieu. And that compensation should come soon after the event, and not “some day”.
TIL is risky, though; too many people accrue TIL and then never get to take it because everything is always busy and always priority 1.
Unless somebody is going to actually be hurt, suffer, or die because you didn't keep working, it's not worth it. You’ll never retire or think on your deathbed, “you know what, 50 hours a week of work wasn't enough - I should have done more.”
Honestly, nobody should work more than about 35 hours a week. At most.