Towger,
Just checked the payslip. Period is "200902" and the dates of payroll period are "16-DEC-08 29-DEC 08", "date of issue 01-Jan-09". The previous payslip was 200852. So to include the relevent two weeks as 2008 would mean having 54 weeks in the year, which I accept is probably unacceptable to the revenue.
However no favours were being done. The pay period in question lies entirely in 2008 and payment was made during 2008, consequently the levy is not deductable.
Looking back over previous years payslips, it appears that only 26 week two pay periods have been allowed per annum, hence 5 days are lost every 4 years. I don't know when the present Dept of Ed payroll system was set up but I reckon that the system has been losing days all along. Until this year, period 02 has ended in Jan (2005 = Jan 3rd, 2006 Jan 2nd, 2007=Jan 1st, 2008 = Dec 29th). This year Period 52 will end on Dec 15th.
How the employer manages the payroll is their problem but they are not entitled to make deductions that do not yet apply (at time of payment) just because the particular payroll system won't handle a problem that should have been foreseeable.
I reckon that this is a payroll mess that will have to be sorted out sooner or later. (in 2020, week 52 will end on Nov 30th!! (OK...I had little better to do than work that one out...sad case...must get out more)) In the meantime the income levy has been applied incorrectly to teachers and probably nurses, gardai etc.