How do i count time starting from particular time...

You can substract your startDateTime from the endDateTime

thanks,ex: if i need to count time starting form 8 AM?

now() - pv!myDateTime

if i try creating a constant for 8 AM and subtracting it from now it is showing some different result. how do i set the constant 8 AM?.

Attached you will find a video explaining this approach

example.swf

thanks for ur help, it did work.

i have one more question when i use now() function with duration being the format it shows 20yrs+ as the output in the application, i need to have it in this hrs:min:sec format.