Probably best to assume govt and banks closed May 1 ,4,5,
I was in CM immigration last week and they said they would be open on the 5 th but closed on the 4 th .but then he asked his colleague and the impression I got was that no one was quite sure...
So the from April 29 to May 8 th there are only two days you can be sure banks and govt etc are open.May 2nd and 3 rd