This is a command-line tool written in Go to keep track of things you want to do each day in your Stardew Valley game, such as whose birthday it is so you can give them a gift, when the Night Market arrives, when the traveling merchant arrives, etc.
I built this app using Go version 1.13.4.
make
bin/stardewcal
It will prompt you for the current season and day in your Stardew Valley game, then tell you if any birthdays, festivals, or other notable events are happening that day. You can keep going forward a day at a time as you play the game.
If you're modifying the app and want to build it and run it in one step, do:
go run cmd/stardewcal/main.go