Timesheets. A way to manage blocks of time more efficiently

Timesheets. A way to manage blocks of time more efficiently

Hi,

I sell blocks of my time and when it's used up invoice out another block of time.

Right now I just run a timesheet report from when they last paid to see how much time is left but this is a bit long winded.

Is there a way for me to set a limit of say 4 hours and then when I perform a task the 4 hours is reduced by the time of the tasks.

Once there's 15 mins left can I recieve an email telling me to invoice out another 4 hours of time.

Can Zoho Invoice do this or is there another app I could use?

Many thanks,

Jon