Presumably that would be the time that the post was made...
It depends on how you access the forums, ie, smart phone, computer, which specific software, etc. Some interfaces only show the date, others show the time if the post was made the current day but only the date with no time on past dates (the popular Android Tapatalk is an example of this later), so that tomorrow there will be no indication of the time the station was heard, only the date will be visible. And of course, some show date and time for every post.
On most forums it is pretty standard to include the time when reporting a reception, and generally in UTC, not local time. Time, date, and frequency are always a good idea, it particularly helps people finding things with historical searches in the future.
T!