PayDates

Our paydays have changed from 10th and 25th to the 15th and the 30th and that is five days after the original pay dates, Can our paydays be from the 8th to the 23rd if not can we go back to the 10th and 25th of every month. When the pay dates fall on Saturday we should be paid on that Friday and if lands on a Sunday we get paid on the Monday.