How can I use multiple clocks share one timer

[ABG]

Notice Board with Calender App

Here's a Button based monthly calendar you can tie to your Sheets back end:

Keep the data separate from the components in a data base.

Need help on a delay and 3x repeat for Arduino Bluetooth

Your app's timing technique could follow the timing technique of this Morse code player: Use your own coding instead of Morse. Send BlueTooth messages instead of vibrating the phone.

You only need one clock if you turn the timing into sheet music.