Heres another I'm working on.. Generally the same as above, but uses additional counters to control on/off periods rather than an rc time..
Basically the counters IC6 & IC7 only count once then reset the counters IC4 & IC5, to properly sync/(or rather unsync) them.. IC4 & IC5 each reset and flip the relay once/daywhen they hit their count.. One of those turns the relay on once/day, and the other turns it off once/day.. A day is however many minutes the counters IC4 & IC5 are set to count.. Both these timers should be set the same.. The number of minutes between plugin, and flip on time are jumpered to the IC6 counter, and the number of minutes from plugin to flip off time is jumpered to the IC7 counter..
So it gets plugged in, all counters start, when IC6 counter hits its total it resets the IC4 counter to zero and turns on the relay.. IC6's job is now complete until the unit gets unplugged because IC4 flips the relay on everytime it resets and begins another day..
Same thing happens with the IC7 & IC5 pair of counters to turn off the relay..
So lets say you wanted a pump to come on for 10min each hour, but you don't want it to come on the first time until 15 minutes have passed..
The 2 diode/jumper banks from IC4 & IC5 are each set to 60..
The IC6 jumper bank gets set to 15
The IC7 bank gets set to 25 (15minute wait+10min duty)
And the process repeats every hour..
A day can be anything from 2-4096 minutes (24hr=1440min)
On/Off periods can be 1-4094min logically..
Minimum 2min is because IC6 & IC7 cannot be allowed to reset simultaneously, so do not set them for the same number of minutes..
The board can obviously be simplified by specializing it to your timing needs instead of making each of those banks fully adjustable from 0-4096 minutes..
BTW, on the right side via IC1 & IC2, the crystal is divided to create a 2Hz clock, which is further divided by 120 to create a 1minute count for easy time management..
I'm also including a simpler version that needs to be manually told when to trigger on the first day period, then repeats the routine after that.. In that circuit, those ugly black marks by pins 4 & 6 of IC3 are normally closed pushbuttons that need to be pressed at the appropriate time on the first day to force reset and sync the IC4 startup counter, and the IC5 shutdown counter.. All circuitry added in the larger scematic is to electronically perform that function thus eliminating the need to be there at appropriate times on the first day..