I would say for at least a week. It's been a while and I don't have a very good memory on this but I would have to say it's around a week.  But you do know you will have to make those days off so it doesn't make sense to me either way! If you have Spring festival and your school is closed they will make you work on the weekends to make those days off...

two weeks, i guess

It depends on what you mean by 'english schools'. If you mean the private Language Training Centres the norm is the minimum 3 days. If this runs into a weekend this can be extended a little (although often you'll have to work the next weekend to make up for it) and very occasionally you may get a week, but that is not common.

There have been a few questions today on this type of subject so for clarity, most contracts for Language Training Centres (i.e. NOT Universities or Government funded Schools) offer the following holidays:

New Year (1st Jan) ---------------------------------one day off

Spring Festival (Jan / Feb) -----------------------three days off

Qing Ming (Apr) -------------------------------------one day off

Labour Day (1st May) ------------------------------one day off

Dragon Boat Festival (June) ---------------------one day off

Mid-Autumn Festival (Sep / Oct) -----------------one day off

National Day (1st Oct) -----------------------------three days off

Christmas Day --------------------------------------one day off (not compulsory but common for foreigners)

All of the above should be paid holidays but that depends on your contract, if your contract says X days you need to clarify that the above listed days count as a working day (that you don't work) also if your contract states X hours then you need to find out how many hours a day off is allocated (otherwise you'll end up making up the hours during the rest of the month).