ENH - Change task schedule on fly

[ManiMozaffar]

Is your feature request related to a problem? Please describe.
A clear and concise description of what the problem is. Ex. I'm always frustrated when I need to stop service in order to change the execution time, so what I want to suddenly change the runtime of my current task to something else, without having to restart service. I don't know even if that's possible or not, but would be very nice to have that kind of access.

Describe the solution you'd like
When I update a task to be executed every 5PM instead of 8PM, then it'd be. I have no idea about how to implement this.