You have a requirement to request leave for some hours (EX: 2 hours), you are able to send the leave request but the calculation in the Vacation Account isnt as Expected.
When the leave request is applied from Self-Services Overview, we have the option for only Full Day and Half Day. There is no partial day.
This is the system behavior and New Leave Request only supports half day and full day leave and not partial day.
Refer below for more insight on the system behavior:
1. If the Time is recorded in the Employee Time Recording (Time Administration work center) then any hours recorded over the Actual Hours will be recorded under Over time
2. if you apply vacation through new leave request option in the Self service then later if you record some time for the same day then the additional time will not go for Over time.
This is expected system behavior.
If you use the SAP pre-delivered vacation time type then system might have throwed a collision error when you record time as described above. But the Time type which you are using is customized and there is no collision rule maintained.
Recording time of Types - Paid Time off and Actual Hours Worked, throws collision errors and hence the system does not allow to record times of these two types together.
These are maintained in the BC - Activity - Time Types - US - Maintain Collision Rules. You have maintained the collisions rules, but the 'Send Message' is not maintained and hence the recording is allowed for him.
Maintain the Send Message for the collisions rules.
KBA , SRD-HR-TLM , Time and Labour Management , How To