Ticks = Ticks + 1
if Ticks = 100 then
Ticks = Ticks-100
Seconds = Seconds - 1
SecondsChanged = 1
if Seconds = 0 then
Minutes = Minutes - 1
MinutesChanged = 1 Seconds = 59
endif

if Minutes = 0 then
Hours = Hours - 1
HoursChanged = 1 Minutes = 59
endif

if Hours = 0 then
Days = Days - 1
DaysChanged = 1 Hours = 23
endif
endif

To my untrained eyes, this would count down the time at every 100 ticks. I guess the issue, if this works, is how to preloaded the timer with the required start time and how to get it to stop at 0.