In the TV show *Friends*, there is the following conversation:

> 
> — Did you ask him?  
> 
>  — No, I haven't had a chance yet.  
> 
>  — I'm kind of on a clock here.  
> 
>  — Oh, Fonzie.  
> 
>  — You know who I always liked? Mork. 
> 
> 
> 

So what does *on a clock* mean? Does it mean "in a hurry"?