When adding a new employee in the middle of a holiday year you should ensure you enter their normal annual balance and not the prorated balance, as the system will automatically prorate the balance looking at their start date and the start of holiday year.

Example:

1. John starts work on 11/07/2014 and is entitled to 20 days in a full year.
2. The holiday year starts on 01/04/2014.
3. 11/07 - 01/04 is 101 days
4. 101/365 days is 27.67%
5. John is entitled to 72.33% of his normal allowance which leaves him entitled to 14.46 days which we will then round depending on your settings for rounding time up

If you had entered 15 in the first place as his allowance, John would now show as only being entitled to 10.85 days which is obviously wrong additionally, you would then have to change his allowance at the beginning of the next year to his normal full value.