To sign calendar, hold your flat, non-dominant hand steady and horizontally in front of your body. Then forming the number 4 sign with your dominant hand, sweep it down before your flat hand with the dominant palm facing out, then sweep your '4' hand horizontally, palm facing in this time. This is like mimicking the grid of a calendar.
Teach your toddler the calendar sign when they start asking you about it and what it is for. Talk about how it helps you remember special days and events, like birthdays, meetings, holidays, or errands.
Teach your child this sign when he or she shows some curiosity about it and its use.