He wasn't there and I was going to ask him out?!?

My last day at work is this monday and ther'es this guy in another department im interested in I'm 50% sure he likes me or likes me enough to be friends with me...anyway..Today is my last opportunity to visit his dept. cause i will have no time for the remainder of my job...so I went there today and I didn't see him in his office...so I stalled...and took care of other errands in his dept...and i passed by again and I don't think he was there still...I don't know what to do I might not be able to go there before monday...I've neever worked with him on any assignments...never contacted him...he'll initate convo with me if he sees me in his dept. so I don't know what to do I want to ask him out!