PLC Timer - Changing the Time

HI,

I want to change retentive timer time in FC block(s7 400).it was 12 hrs heating cycle and 12 hrs cooling cycle before and my requirement to change to 14 hrs heating and 10 hrs cooling.i tried to change in fc block but not available there and mentioned there in db block address and i went there to change in db block and typed in actual value and changed actual value but not changed in initial value.it is changed here in fc block also when i typed in actual value.but still is running 12 hrs cycle only.

how to change timer time in fc block or db block?pls advice me