Save the Date, is like a notice which states the date of a significant event. This notice is usually sent to those who can be affected by these events. Save the date, is like selecting the date i.e. day for some special ceremony. This ceremony or event can be of any type e.g. party, dinner etc. Usually Wedding/Marriage is such an event on which these save the date is decided and then invitation/cards are mailed to the relatives and friends.
There can be many occasions, events and ceremonies for which a day is saved. Save the day is just another name of save the date. It means we save the selected only for the special event and all other works are put aside. Only that event has an importance on this day or date. It can also mean a date for a dinner, or the whole day. It can also means putting aside all of your works for a special person.
Save the date is usually done for marriage ceremonies. Most of the people have seen a phrase “save the date” or “save the day” on the marriage card. Although this notice can be used for other event rather than wedding. This event can be social gathering, dinner, parties, entertainment occasion and other event. Here are some of the cute save the date cards and invitations. Have a look at it: