For that set the counter Accumulators to the present date & time, set the Presets to one over the max (second & minute = 60, month = 13, day of month = 32)
You will have to add a year counter to determine if February is 28 or 29 days.
Have your 1 second timer count a Seconds timer then SUB 100 from it.
When the second counter is Done count a minute & RES the second counter.
When minutes count is done count an hour and RES minute.
Have hour count day.
Have day count month. But don't RES day - MOV 1 to .ACC
Have month count year. But don't RES month - MOV 1 as above.
Now for 30 day months:
If the day is 31 and the month is 4, 6, 9, or 11 then count a month and MOV 1 to day
Now for leap year:
If the month is 2 and the day is GEQ 29 DIV the year by 4 and save it to an integer, then DIV by 4 again and save it to a Float. Compare the integer to the float and if they EQU it is a leap year - OTE a "It's A Leap Year" bit
If the month is 2 and the day is 29 and your bit is NOT on then count a month and MOV 1 to day. If your bit IS on wait until the day is 30 and the month is 2, then count a month, MOV 1 to day
If you have a HMI for this I would add lines to display all the counter.ACC's, change them as needed, and add a Reset Second To :00 PB to calibrate it.
Then to run your pump do a LIM Month.ACC to when you want and set a "Run The Pump" bit. If you don't want the pump running 24 hours then check the hour and minute as wanted.
To account for days of week you could also have the Hour counter add 1 to a DayOfWeek counter, set PRE to 7 and RES it when done to follow the RSLogix norm of Sunday=0, Saturday=6.