Mark your calendars vs mark your calendar

Examples:

• Mark your calendars for the upcoming concerts.
• Don't forget to mark your calendars for the company's annual conference.
• We have several exciting events planned, so mark your calendars!
• Make sure to mark your calendars for the release dates of these movies.
• The school has announced the exam schedule, so mark your calendars accordingly.

Alternatives:

• Remember to put these dates in your calendar.
• Don't forget to note down these important dates.
• Make sure to save these dates.
• Keep track of these dates.
• Don't miss out on these events.

Examples:

• Mark your calendar for the deadline of the project.
• Don't forget to mark your calendar for the meeting with the client.
• Make sure to mark your calendar for the concert next week.
• The release date of the new book is approaching, so mark your calendar.
• The event is on a specific date, so mark your calendar accordingly.

Alternatives:

• Remember to put this date in your calendar.
• Don't forget to note down this important date.
• Make sure to save this date.
• Keep track of this date.
• Don't miss out on this event.