From when to when?

[backspace2062]

Boss: can you work tomorrow?
Employee: yes, but from what time to which time you need me?

would you think the answer of employee looks ok?
Regards

 

[MikeNewYork]

Boss: can you work tomorrow?
Employee: yes, but from what time to which time you need me?

would you think the answer of employee looks ok?
Regards

I would say, "When do you need me?"

 

[Rover_KE]

Your thread title is a good enough question in this context.

Rover

 

[Raymott]

Boss: can you work tomorrow?
Employee: yes, but from what time to which time you need me?

would you think the answer of employee looks ok?
Regards

I'd say, "Sure, what hours?"