This circuit is from American documentation from the 70s. The circuit makes use of the operating system of the time, but it can be implemented with more modern equivalents.
We found this circuit in the October 1992 Radio Electronics magazine. The frequency is given by C1...
This conventional LED flasher circuit has a configurable multivibrator configuration with PNP...
This extremely slow circuit produces one pulse per month and can be used in a timer. We found it...