Generating negative hours to deduct from salary using time calculation rules

Summary

Generating negative hours to deduct from salary using time calculation rules

Content

Have anyone tried generating unpaid time as negative hours which can be deducted from salary. We know unpaid time can be entered as absence and setup to be deducted from salary. However we have requirement to generate the unpaid time using time calculation rule and I don't think we can auto generate absence hours using time calculation rule. Any inputs will be very much appreciated.