With a little work, you could probably adapt this idea to any number of circuits out of the 555 playbook, like a PWM generator, for example. There’s almost nothing a 555 can’t do.

“Arduino Self-Timer” project presented here is a low-component count 60 seconds countdown timer. It can be powered from a 9V compact battery or suitable Arduino AC mains adaptor. Working of the ...

The programmable timer features and up counter, down counter, and point accumulator that can be programmed manually using only one on-board button, or digitally with your Arduino or Raspberry Pi.

You have a timer and clock in just about every single device out there these days, but if you want to build you own, Instructables user GeraldF6 shows you how to do so with a Arduino. The project ...

[Scott-28] recently sent in a particularly well-documented project that turned an antique rotary phone into a digital kitchen timer using an internal Arduino.