Location: L'ville, GA
Can be done but a bit tricky.
Build scan formula as usual, then "and" it (in paren's) with:
Baryear()=yyyy and barmonth()=mm and bardayofmonth()=dd
THEN, to get OScan to apply that rule to all the loaded bars,
Insert entire formula into this: Sum((formula),250) < 0
The inserted formula, wrapped in parens, returns its true/false result as -1 or 0. The Sum function adds up the returned values for the past 250 bars. So, when the formula "hits" the day you specified, it will return -1 only if your other scan criteria are valid for that day. All the other days will return 0 since the date specs don't match. Voila!
However - note that OScan natively only loads in the most recent 250 daily bars, so if you want to go back further, you need to change the config file - and Barry dis-recommends doing that (not sure why).
If you are using MarketScan intraday timeframes, you can also include barhour() &/or barminute() in the specifier.
[Edited by Jim Dean on 8/19/2017 8:16 AM]