Can we use the phrase save this day instead of save the date? The intention is to emphasize an event happening on a special date. For example, a soccer match is going to happen next Friday and I want to say Save this day! Is it correct?
Save the date or mark your calendar would be customary. Save this day would be acceptable, but not as common.
I would not use save the day, as that phrase more commonly uses a different sense of save, to rescue or safeguard. If someone were to save the day in reference to a soccer match, I would think of a player who attained victory for the team when defeat was imminent, such as scoring a last-minute goal or preventing a tying goal.
"Save this day" might work if the event is going on for the entire day, and the guests literally will have to save the whole day for your event.
If your function or event is going on for, say, an hour or two, I think "date" would be the more appropriate word, not only because convention tells us so, but because using the word "day" might imply something else - like the event going on for much longer than the one or two hours.
What comes to mind is this example:
"Don't worry, I'll be sure to save that day for you, and only for you."
"Don't worry, I'll be sure to save that date for you, and only for you."
The first would mean that you're putting aside that entire day for that person. While in the second one, it sounds a bit more ambiguous because it could just mean a dinner date, or it could also mean the whole day.
Why not use plain English and simply announce the event?
We are happy to announce our wedding will be next June 10, 2013. Formal invitations with details and RSVPs to follow.
Please join us for the ABC Conference May 13–18, 2014 in Seattle, WA, USA.
The next soccer match is next Friday.
Friends and relatives, wonderful news, our wedding will be on the long weekend in August in 2013 in Smithville, IL. We're sending this advanced notice in the hopes you can plan to join us.
It’s implied if someone is intending on attending, they will mark the dates on a calendar and reserve the date anyway. No need to instruct them to “save the date”, it’s understood (don’t treat your guests like they are dummies and don't know what to do).