既可数又不可数，具体要看实际表达的含义。时间的英文是“time”，time表示“次，回，倍”时是可数名词；表示“时期，时代，境况，当代”时用复数形式；表示“时间”为不可数名词。例句：Time dragged terribly.意思是时间过得真慢。
time的用法
1、It's time for sth . 或 It’s time ( for sb . ) to do sth. 意为：该是……的时候了
This is the time when sb . should do sth . 或The time has come when sb . should do sth . 这两个句型也用来表示“该是……的时候了”,when 引导的定语从句用陈述语气或“should + 动词原形”的形式。例如：This is the time when you should get up .是你该起床的时候了。
2、It's time that...中,that从句中的谓语动词用过去时或用"should+动词原形"(should不能省略)。
It's time we started.(It's time we should start.)
3、This is the first ( second , last ) time ( that ) sb . has done sth. 意为：是某人第几次……。
This is the third time I have been to Beijing . 这是我第三次去北京了。
time的例句
1.You're wasting precious time!
你在浪费宝贵的时间！
2.We killed time playing cards.
我们打纸牌消磨时间。
3.There's no time for delay.
没有时间了，不能拖延了。
4.Unfortunately, my time is limited.
遗憾的是，我的时间有限。
5.We didn't have much time.
我们没多少时间。