Is it possible to travel outside China for 4 days then comeback with one month z type left.

my visa will expire in August 2,2016. And my contract will expire in august 28,2016. I'm planning to travel on June 30 to July 2,3016 to Singapore.Is it possible to come back in PRC with one month left before it expired.but I'm planning to re new my Z type again and my work is still on going when I comeback after the trip.