The Bhutanese calendar –
Scroll down for list of calendars available.
On this page are available both an archive of calendars from the Bhutanese tradition together with open source software for creating the calendar (scroll down to access the list of archived calendars). Bhutan calendars are very similar to those in the Tibetan Phugpa tradition, but with certain values used in the calculations being different. The most obvious difference with the Phugpa and all other calendars is that the weekdays are one ahead of all others. So, if today is a Wednesday in the Phugpa, Tsurphu, and Gregorian calendars, in Bhutan it is a Thursday. Also, in the Bhutan tradition, an intercalary month takes the name and qualities of the month preceding it rather than the one following it.
The main text for the definitions of the Bhutanese calendar is the "rtsis gzhung gdan dus thun mong gi nges pa gsar du bkod pa dang bcas pa'i lag len lhan thabs gsal ba'i sgron me", by "lha dbang blo gros". In that text the epoch given is 1754, and so in the following, Bhutanese calendars were originally listed from 1755 onwards (up to 2049). However, I have been asked to extend the listing, and now the years 1600-2099 are covered. It should be understood that years before 1754 may not be relevant in historical references. Please scroll down and click on the year for which a calendar is required.
The basic epoch data used to produce these calendars, from the text by "lha dbang blo gros", are given on this page. Note that he uses a slightly different mixed-radix system from the Phugpa tradition, but his mean motions of the Sun and Moon are in fact identical.
To access the software and source code used to create these calendars, click here:
If you find any errors in this software, or have any comments, suggested changes or additions, please address these to Edward Henning.
The Bhutan government publishes on-line a list of holidays for any year, not long before the beginning of that year. In order for people to be able to plan ahead, it has been suggested to include these holidays in the calendars published on this site. This has been done from version 1.20 of the software available here.
These data have been included in the calendars available here from the current year, up to 2020. Some of the holidays are dependant on certain individuals, such as the current king, and so are not relevant for all editions of the calendar. The holidays that are included will be updated, and perhaps others added, as further information becomes available.
For each of the following holidays, the style in English is as given on the Bhutan Government web site during the few years prior to 2011, together with the Dzongkha (Tibetan) if they are listed in Bhutanese almanacs during a similar period of time. Some holidays are set according to the Bhutan calendar, others according to the western Gregorian calendar. First, those that are fixed according to the Bhutan calendar:
1, 1st Month: New Year, 2 days. (lo gsar ngal gso.)
10, 3rd Month: Death Anniversary of Zhabdrung. (zhabs drung sku mchod ngal gso.)
15, 4th Month: Lord Buddha's Parinirvana. (dus chen lnga 'dzoms kyi ngal gso.)
10, 5th Month: Birth Anniversary of Guru Rinpoche. (gu ru'i 'khrungs ston ngal gso)
6, 8th Month: Thimpu Drubchen (Thimpu only).
10, 8th Month: Thimphu Tshechu (Thimpu only), three days.
22, 9th Month: Descending Day of Lord Buddha. (lha babs dus chen ngal gso)
1, 12th Month: Traditional Day of Offering. (snga srol 'bul ba'i lo gsar ngal gso)
The following are set according to the Gregorian calendar:
2 January (approximately): Winter solstice. (dgun nyi ldog gi ngal gso.)
21 February: Birth Anniversary of His Majesty the King, 3 days. (brgyud 'dzin lnga pa'i 'khrungs skar ngal gso.)
2 May: Birth Anniversary of the 3rd Druk Gyalpo. ('brug rgyal gsum pa'i 'khrungs skar ngal gso.)
11 November: Birth Anniversary of the 4th Druk Gyalpo and Constitution Day. (rtsa khrims kyi nyin dang brgyud rgyal bzhi pa'i 'khrungs skar ngal gso.)
17 December: National Day. (rgyal yongs dus chen ngal gso.)
The timing of the winter solstice is unusual in a couple of respects. The Bhutanese use a value for the solar longitude at solstice of 18;45,0 – a little different from the Phugpa value of 18;31,30. The Bhutan value is equivalent to 250° (the Phugpa value is equivalent to 247°). Not only is this the wrong value for the solar longitude at solstice, the Bhutanese calendar makers also use, instead of the calculated true position of the Sun, the mean value. Currently, the Bhutanese timing of the solstice is usually 2 January, but due to the errors in the calendar, this will vary and also drift over time, moving later in the Gregorian calendar.
To access individual calendars, click on the relevant year below: