I want to create a simple job time entry form.

Job Name

Start Time

End Time

Work Date

and show the job hours and minutes on the form.

The users would access this from their Android smart phones.  This is the rub.  The DateTime control is unusable on the smart phone I'm testing on.  I can pick a date or click to make hours and minutes increase but decreasing them seems impossible as you can't hold shift and click.  (Android 4 device - Note 2).

Every way I've tried to do it without the datetime field runs into gobs of code with deal breakers like;

formula field can't call user function and

formula field can't call formula field.

Any ideas?  What online form technology would make this doable?

Thanks,

Dennis