Daily League Sudoku #23: Sum or Difference Sudoku

This week a Sudoku variant themed around today's date. I did it once before for Valentine's day. I somewhat stumbled into it, while just messing around with a few ideas for a Sudoku. I put down a 3 and an 8 and figured I could push it through the whole puzzle. It's split down the left bottom and right top diagonal. It's not too hard a puzzle after realising the opening. Enjoy.
The puzzle is a bit late, but I had to remake part of it as part of the logic was incorrect. Hopefully this one is without error.

Recap of the last Daily League week:
Sunday: One of Eight Sudoku by Seungjae Kwak
Monday: Pairs Sudoku by Jakub Hrazdira
Tuesday: Domino Sudoku by Prasanna Seshadri
Wednesday: Frame Sudoku by Bastien Vial-Jaime
Thursday: Odd-Even Antiknight Sudoku by Rishi Puri
Friday: Nonconsecutive Sudoku by Tom Collyer

Daily League PDF's:
Week 28

Rules for Sudoku

In this Sudoku, a number between two cells indicate either the sum of or the difference between these two cells.
[Edit: Puzzle image adjusted as one of the clues was missing]