It does matter. Lets say at a pilot calls in sick for a trip on 21 APR at 6:30 am for a trip that departs at 3PM on 22 Apr. If you have checked yes you will be awarded the trip. If you have checked no you wont get it unless no one WS the trip in the 7am window. It would then go to the manual process for same or next day coverage and you would be awarded the trip a few hours later.
Keep in mind that all known flying for same or next day coverage after the 7am window the day prior must be covered as it shows up. It will not be covered by PCS. Schedulers have however been known to let a trip for the next day season in the pot for a few hours hoping someone WS's the trip if they are out of reserves. This is actually not legal but they will claim they were busy with other trip coverage. Also keep in mind that any WS awarded for same day with less then 12 hours to report is a proffer.