at (some time) sharp

At an exact time, with the emphasis that one must not be late. We need to leave for the airport at 8 AM sharp tomorrow morning. Please be here at 6:30 sharp.

Common Names:

Name	Pronounced	Usage
Cenhelm	-	Anglo-Saxon
John	JAHN (English)	English, Biblical
Porsche	PAWR-shə	English (Modern)
Domitilla	-	Italian, Ancient Roman
Gluke	-	Yiddish
Meryl	MERL, MER-əl	English