As much as I love and agree with the info shared in the Text Expansion episode of the podcast; I already have Keyboard Maestro and I really want to avoid another subscription.
So instead of buying Text Expander, I made a series of Keyboard Maestro macros to help me with typing out the day and date. Instead of typing in an email “this Monday” by hand I type “;thismon” and get “this Monday (04-29-19)” automatically.
Here is a post I wrote about it that had a link to the macro group post I have this and next for every day of the week as well as Today and Tomorrow.
I hope they save you some time!