How do I keep from getting a #VALUE! error with text in this situation?

[SuperNoodle]

Listen, first off I want you all to know that I've searched high and low for the answer to this question but I realize I may not know the terminology enough to find what I'm looking for. So I apologize in advance if this question has been asked.

I'm making some schedules for my employer and I've hit a snag. It currently works as intended, but the problem arises from my management staff. I'm using a MOD function to tally up the hours from scheduled times, and I want to able to allow users to type in the words "ro" and "off", because that's what they're used to doing. Of course at the current moment any written text will foul me right up and produce a VALUE! error. I think I can use a "IF isnumber" type of formula, but I'm not too savvy on how exactly to do it. Any help would be so appreciated, and thanks in advance!

 

[DanteAmor]

In the cell write "ro" or write "ro" and a number?
In which cell they write "ro" can be in C7 or in C7 or both?

What do you want as a result if there is a text?
In the following example, if there is an error in the formula, a zero returns:

=IFERROR(MOD(C8-C7,1)*24,0)

 

[jratten]

Here you are. You will need to accommodate for text being entered into either the start or stop time cells. IF(AND(ISNUMBER(A2),ISNUMBER(B2)),MOD(B2-A2,1)*24,0)

 

[SuperNoodle]

In the cell write "ro" or write "ro" and a number?
In which cell they write "ro" can be in C7 or in C7 or both?

What do you want as a result if there is a text?
In the following example, if there is an error in the formula, a zero returns:

=IFERROR(MOD(C8-C7,1)*24,0)

In cells C4-5 or in C7-8 would be where they would want the text to be, in place of the scheduled in and out times. If there is a text there I would like for the formula to ignore it.

I just tried your suggestion and that works perfectly! Thanks so much DanteAmor for your time and help!

 

[SuperNoodle]

Here you are. You will need to accommodate for text being entered into either the start or stop time cells. IF(AND(ISNUMBER(A2),ISNUMBER(B2)),MOD(B2-A2,1)*24,0)

Thanks for the quick reply and the screen shot. You all on this site rock! I wished I'd had found you guys when I was taking data mining QM during my undergrad!

 

[DanteAmor]

I just tried your suggestion and that works perfectly! Thanks so much DanteAmor for your time and help!

I'm glad to help you. Thanks for the feedback. ?