One option is occasion.
Occasion.
occasion
That's from an Easter Event some years ago; players who finished that event can turn into Easter eggs. If you didn't do the event, there is no way you can "catch up" now; that was a one-time-only event.
Tense Shift
You can only obtain Arceus through a Nintendo hosted event. But, the event might be distributed through WiFi download so, everyone with WiFi can enjoy the best Pokemon of all time. (Once you get the event Arceus is supposed to be able to be caught in the "Hall of Origin" which appears after you download the event.
Occasion.
occasion
An invitation letter invites someone to an event. The invitation letter provides the time and date of the event the person is invited to.
Duration
At this time
Initial time generally refers to the starting point of a specific period or event. It is the beginning of a particular timeline or duration.
"Afterwards" is an adverb. It is used to indicate something that happens after a particular time or event.
Seasons
Beforehand means before time or advance in time or need, while before means earlier in time or previously.e.g, Beforehand: If you pay the bill beforehand, you will get a discount of 2 percent.Before: I reached the venue before he reached there.
Save the Date magnets are mainly used for Weddings, but can be used for any event. They are just used to give people plenty of time for preparation for the event,
if u do something or if something happens afterwards, you do it or it happens after a particular event or time that has already been mentioned
No, it is not a preposition. The word afterwards is an adverb.