It's Monday. You know what that means...
It's time to change the oil!
Don't bother trying to avoid it. It's not like it's going to get done by itself. Or that the universe will magically lubricate your time machine for you. Nope.
So, here's a special deal just for you, our valued customer!
We'll change the oil in your time machine, and even toss in some synthetic for good measure! (Don't worry, it's not like the oil's going to expire or anything)
Price: 1000 spacebucks (a special Monday-only price)
Time travel is not our responsibility. We are not liable for any paradoxes, temporal anomalies, or spontaneous combustion caused by our services.