date as a foreign key

I have a master

table Task (
start_date date unique key,
<parameters>

)

and a detail

table TaskStatement (
start_date date foreign key references Run.start_date,
<etc>

)

I was told that it is bad idea to use date as a foreign key, but I didn't hear a convincing argument. Use sequences instead? Well, much have been said about surrogate keys already. We can start 2 tasks at the same time? Not if lanching them manually;-) besides, I put explicit constraint -- unique key -- to prevent this. Am I missing anything else? Received on Wed Sep 19 2001 - 11:44:33 CDT