How many weeks apart are the two May bank holidays?

·Published: 16 September 2026

The two May bank holidays are normally three or four weeks apart: a gap of either 21 or 28 days. The early May bank holiday follows the first Monday in May rule, while the spring bank holiday follows the last Monday in May rule. The interval therefore depends on how the Mondays fall within that particular May. A month with four Mondays produces a three-week gap; a month with five Mondays produces a four-week gap. These figures measure the difference between the two holiday dates.

Where the two Mondays can fall

The first Monday of May must fall between 1 and 7 May, inclusive. If the month begins on a Monday, the early May bank holiday is on 1 May under the usual rule. If it begins on a Tuesday, the first Monday does not arrive until 7 May. Each of the other possible starting weekdays places that first Monday somewhere between those dates. The holiday is therefore defined by its position in the week and month, rather than by a fixed date such as 1 May.

The last Monday of May must fall between 25 and 31 May, inclusive. May always has 31 days, so those seven dates form its final seven-day stretch. There is exactly one Monday within that stretch. A Monday on 24 May cannot be the last Monday because another follows on 31 May. Conversely, once Monday falls on 25 May or later, the next Monday will be in June. This explains why the spring bank holiday can move across the final week of May under its normal rule.

Why the interval is 21 or 28 days

Successive Mondays are seven days apart. Starting with the first Monday, the second is seven days later, the third is 14 days later and the fourth is 21 days later. If a fifth Monday still fits inside May, it is 28 days after the first. Every May contains at least four Mondays, but a 31-day month cannot contain six. The first and last Mondays must consequently be separated by either three weekly intervals or four. Counting the Mondays themselves gives a different number from counting the gaps between them.

The deciding detail is whether the first Monday falls within the first three days of May. If it is on 1, 2 or 3 May, adding 28 days gives 29, 30 or 31 May, so a fifth Monday fits. If the first Monday is on 4, 5, 6 or 7 May, adding 28 days takes you into June. In those cases, the fourth Monday is the last one in May. All seven possible date pairs can therefore be written down without choosing a particular year:

• 1 May and 29 May: 28 days apart.
• 2 May and 30 May: 28 days apart.
• 3 May and 31 May: 28 days apart.
• 4 May and 25 May: 21 days apart.
• 5 May and 26 May: 21 days apart.
• 6 May and 27 May: 21 days apart.
• 7 May and 28 May: 21 days apart.

You can also work out the interval from the weekday on which May begins. A May starting on Saturday, Sunday or Monday has five Mondays, giving a four-week gap. A May starting on Tuesday, Wednesday, Thursday or Friday has four Mondays, giving a three-week gap. This is a useful shortcut when looking at a calendar: check the position of 1 May, then follow the Monday column. There is no need to count every individual day between the holidays.

Examples of both calendar patterns

In 2026, the first Monday is 4 May and the last is 25 May. The Mondays are 4, 11, 18 and 25 May. Subtracting 4 from 25 gives 21 days, or three weeks. Notice that there are four Monday dates in the sequence but only three steps from the first to the last. In 2027, the first Monday is 3 May and the last is 31 May. That sequence includes 3, 10, 17, 24 and 31 May, creating four steps and a gap of 28 days.

The same reasoning applies when the first Monday is at either extreme of its possible range. In 2028, it falls on 1 May and the last Monday falls on 29 May: a four-week interval. In 2029, the first Monday falls on 7 May and the last on 28 May: a three-week interval. An earlier first holiday can leave room for an additional Monday before the month ends. These examples apply the ordinary first-Monday and last-Monday rules; the calculation describes that recurring pattern.

What counts as the gap?

When someone asks how far apart two dates are, the usual answer is the elapsed number of days from one to the other. On that basis, 4 May to 25 May is 21 days. If you instead count only the dates strictly between the holidays, excluding both Mondays, there are 20 dates. Including both holiday dates gives 22. For a four-week interval, the corresponding totals are 28 elapsed days, 27 dates strictly between them, or 29 dates including both endpoints. Stating the counting method prevents an apparent disagreement.

For a quick calculation, locate the first Monday in May and add 28 days. If the result is still in May, that is the last Monday and the gap is four weeks. If the result lands in June, add 21 days to the first Monday instead, giving a three-week gap. This method uses calendar days, including Saturdays and Sundays. The central check is simply whether May has four or five Mondays, with the holiday dates marking the first and last of them.