Of course, in a universe where time travel exists, we will need to expand English grammar to include tenses to cover these kinds of eventualities. For example, in the second panel, Dilbert uses the present perfect tense to describe something he will finish in the past (note the time travel reference).
If English had the proper tenses, Dilbert should have used the Present-Past Continuous tense and it would go something like this: "You have me was finishing two weeks before I start." Alternatively, the Present-Past Perfect Continuous version would be "You have me had been finishing two weeks before I start." or the simpler Present-Past Perfect tense "You have me had finished two weeks before I start."
These tenses get complex. For example, the Future-Past Continuous Perfect tense would be "You will have me had been finishing two weeks before I start."
Sounds ludicrous. Maybe it's a good thing time travel doesn't exist...
I worked on one project where the project manager completed the final MS Project plan about a week after we wrapped up the project. He got promoted eventually. A lot of good people who did actual work got laid off later when the company hit tough times. (I think my dislike of Project Managers is pretty obvious. They have one function: to generate paper for management.)