It's important to know that there are:

7 days in a week

14 days in a fortnight

52 weeks in a year

365 days in a year

366 days in a leap year

Also, we should know the number of days in each month:

You could learn this poem:

30 Days has September,
April, June and November.
All the rest have 31,
except February which has 28,
until a Leap Year gives it 29.

Let's have a go at some questions now.