It is used to let you know of an important event so that you do not make other plans on that date,
January 23, 2015
It means "reserve this date."
For example. Someone can send a wedding invitation for a wedding scheduled to occur on 10/1/2016. "Save the date" means please remember to not schedule anything else on this date.
January 22, 2015
Still haven’t found your answers?
Write down your questions and let the native speakers help you!