The Buckets by Greg Cravens for December 14, 2015
Transcript:
I was going to have asked for a time machine for Christmas, but I won't get it. Why do you think that might be, Einstein? Because by now, I would have gone back and will have had taken myself forward in time to enjoy Christmas with my time machine! But I didn't, and I'm not, so I won't have gotten it! I think you clobbered the future tense, on the way to future hysterical.
The Dr. Who reference was close. I’m a big Douglas Adams fan. His first Dirk Gently book was originally a Dr. Who script.