Mathematics K–6 · Years 1–2

Calendar count: dates and the days between events

Measurement and space

Practical, model not builtLow risk

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The idea

A calendar sets out the days in rows of seven, so the days between two dates are counted as whole weeks down the columns and extra days along a row, and the months have different lengths.

What you need

a printed calendar of the current year, one month per page
a large class calendar for the current month
coloured sticky dots for marking events
the dates of three real class events supplied by the teacher (for example a sports carnival, an excursion and the last day of term)

How to do it

Find today's date on the class calendar and read it in full: day, date, month and year.
Mark the three events with dots. For each, count the days from today by counting whole weeks down the columns (7 days each) and then the extra days along the row.
Check one count by counting the days one at a time.
Record the number of days in each month from the printed calendar in a table. Find the months with 31 days and the month with the fewest.
Count the days from 25 March to 5 April and explain how the end of March was counted.
Find the day of the week for the first day of the next month and check it by counting on from the first day of this month.

What you should see

Counting by weeks gives the same answer as counting by ones, faster: from 3 March to 17 March 2027 is 2 weeks, 14 days. The table shows seven months with 31 days, four with 30 and February with 28 days in 2026 and 2027 and 29 days in 2028, making 365 or 366 days in a year. From 25 March to 5 April is 11 days: 6 days are left in March after the 25th and 5 more follow in April. 1 January 2027 is a Friday; 31 days later is 4 weeks and 3 days, so 1 February 2027 is a Monday.

What changes

This activity lists no variables to change, measure and keep the same.

Common misconceptions

Each of these ideas is wrong, and the activity is a chance to test it.

Every month has 30 days.
The days between two dates include both the start day and the end day.

Safety card

Low riskLearners carry it out

Hazards

none beyond an ordinary classroom

Controls

none needed

Note

No chemicals or heat are used, so the NSW Department of Education Chemical Safety in Schools package is not needed; ordinary classroom supervision under the school's usual risk management.

Curriculum references

The NSW syllabus outcomes and Australian Curriculum v9 codes this activity supports. They are references, not a verified or complete curriculum alignment.

Mathematics K-10 Syllabus (2022), NSW Education Standards AuthorityMA1-NSM-02 MAO-WM-01
Australian Curriculum v9AC9M1M03AC9M2M03

Sources

The pages the author read to write this activity.

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