The IRD deems that all salary and wages are taxable in the year in which payment was made. This is irrespective of when the work was or will be performed.
If you have a Period End date that falls on or after 1 April, but your employees are paid on or before 31 March, you will need to change your Period End date to be on or before 31 March.
For example, a group of employees are to be paid on 31 March for work performed from 26 March to 2 April. The normal Period End date is 2 April. The Period End date must be changed to 31 March (or earlier).
If the Period End date is on or before 31 March, but employees are paid on or after 1 April, then the Period End date must be changed to 1 April or later.
Please remember that you will need to adjust your next Period End date when performing the Pay End process to be in line with your regular Period End dates.