Please note: this was written in 2020 but also applies to 2023. Vassa starts on August 1, 2023.

There seems to be confusion about when vassa is this year. This year is a special year and Vassa starts the day after the full moon day in August. The full moon day is August 3rd and Vassa starts on August 4th.

However, there are some traditions that believe that Vassa has already started with the full moon day of July 4th and Vassa on July 5th.

Who is correct?

Today we will explain how the two calendar systems work and which one should be followed.

The Buddhist Calendars follow the lunar calendar. We all know that the uposatha day is on the new and full moon cycles, with small uposathas on quarter moon cycles. We do not follow the Christian calendar and practice our religious day on Sundays. Do you agree?

Buddhism follows the moons.
Vesak is based on a full moon day
Dhammacakkapavatthana was based on a full moon day.

We don’t use the Solar Calendar.
We use the Lunar Calendar.

Because of this, we need to do some math and adjust for difference of the sun and the lunar calendars because winter would be summer and summer would be winter if we did not make adjustments.

Even the Solar Calendar has 1 day added for every four years. This is called leap year.

The Solar Calendar is 365 days per year.
The Lunar Calendar is 354 days per year.
The Lunar Month is 29 days and 12 hours and change.

From Wikipedia

The difference is 11 days per year.

In 8 years there are 88 days. Or three months. So, we have to adjust every 8 years. Why 8 years?

8 x 11 is 88 and that is divisible by 29 days or the Lunar Month.

So we adjust the time lag in 3 separate times.
3 years
3 years
and 2 years.

3 + 3 + 2 is 8 right?

So in the Lunar or Moon Calendar we must add one lunar month or 2 pakkha to the Hot Season. There are normally 8 pakkha (new or full moon cycles), in a season. However, this Hot Season for this year has 10 pakkha (or the extra added lunar month).

Rainy Season comes after Hot Season, and now the rain is just starting to fall on a more regular basis in Myanmar . The lunar calendar is good for judging the weather. So plan your vacations accordingly!

So normally we add an extra month every three years.
This year is the year where we do this after 2 years.
3 + 3 + 2 = 8
Is that right?

And so there you have your answer about which calendar is correct. Some traditions follow the Lunar Calendar while others follow the LuniSolar calendar (Solar mixed with full moons).

Remember Buddhism follows the Lunar Calendar. This is also followed in India. They have two calendars. One is from the British Rule and the other is for the Hindu/Buddhist roots.

So, for this reason Vassa or The Buddhist Rainy Season starts the day after the full moon of August 3rd. Vassa Starts on August 4th.

You might have noticed that some people celebrated Vesak (The Buddha’s Birthday, Enlightenment and Death) on two different months. This was for the same reason. This year the Lunar or Buddhist Calendar adds an extra lunar month. The next Lunar Leap Month will be 3 years from now, so mark your calendars!

So practice well and practice correctly this upcoming rainy season on August 4th.
Aloha!

Below is a video of Sayadaw U Kumarabhivamsa who shared this information with me in detail. Aferwards, we made a less complex video for you all to watch.

• pa-auk
• rainy-season