For those of you who still struggle with the public holiday arrangments in China I thought I'd post the system at my work:
1) The holiday period is from April 30 to May 2 (that is, Saturday, Sunday and Monday ).
2) If you normally have classes on Saturday, you'll still teach on April 30 (Saturday).
3) All teachers will be off work on National Labor Day May 1 (Sunday). [Gee .. thanks!]
4) If you normally have classes on Sunday, you should make them up on May 2 (Monday).
5) Classes on May 2 (Monday) are cancelled without any need for a make-up.
Hope that is perfectly clear now. :)