it is common in english to ask people about their holidays. in the west many families go away on holiday during the summer months and so it is very usual to ask about this. if the holiday has not yet taken place, then their holiday plans can be talked about. and if it is already over, then where they went, whether they enjoyed it and so on can be discussed. similar questions are asked before festivals and pubic holidays.
foreigners living and working in china often have frequent opportunities for travel, either at weekends or during their holiday periods, so questions on this topic can often lead to fruitful discussions. they may be particularly interested to hear comments on which places are worth visiting and why, especially if these places are a little less well known and not clearly described in the tour guides.
take vacaticn and long weekends. never let vacation time expire.