The Bhutanese calendar –
Open source software and calendar archive


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 It should be understood that years before 1754 may not be relevant in historical references.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:

Version 1.00Original version.
Version 1.01New Win32 command line version to support Windows Vista and Windows 7. See the "Windows compatibility" box here for further details. This version 1.01 is otherwise functionally the same as v.1.00.
Version 1.20Code has been tidied up, with much old or debug code removed. Bhutan holidays that are currently in use have been included; for further details see below

If you find any errors in this software, or have any comments, suggested changes or additions, please address these to Edward Henning.

Bhutan holidays

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.

Calendar archive

To access individual calendars, click on the relevant year below:



1600 1601 1602 1603 1604 1605 1606 1607 1608 1609
1610 1611 1612 1613 1614 1615 1616 1617 1618 1619
1620 1621 1622 1623 1624 1625 1626 1627 1628 1629
1630 1631 1632 1633 1634 1635 1636 1637 1638 1639
1640 1641 1642 1643 1644 1645 1646 1647 1648 1649
1650 1651 1652 1653 1654 1655 1656 1657 1658 1659
1660 1661 1662 1663 1664 1665 1666 1667 1668 1669
1670 1671 1672 1673 1674 1675 1676 1677 1678 1679
1680 1681 1682 1683 1684 1685 1686 1687 1688 1689
1690 1691 1692 1693 1694 1695 1696 1697 1698 1699

1700 1701 1702 1703 1704 1705 1706 1707 1708 1709
1710 1711 1712 1713 1714 1715 1716 1717 1718 1719
1720 1721 1722 1723 1724 1725 1726 1727 1728 1729
1730 1731 1732 1733 1734 1735 1736 1737 1738 1739
1740 1741 1742 1743 1744 1745 1746 1747 1748 1749
1750 1751 1752 1753 1754 1755 1756 1757 1758 1759
1760 1761 1762 1763 1764 1765 1766 1767 1768 1769
1770 1771 1772 1773 1774 1775 1776 1777 1778 1779
1780 1781 1782 1783 1784 1785 1786 1787 1788 1789
1790 1791 1792 1793 1794 1795 1796 1797 1798 1799

1800 1801 1802 1803 1804 1805 1806 1807 1808 1809
1810 1811 1812 1813 1814 1815 1816 1817 1818 1819
1820 1821 1822 1823 1824 1825 1826 1827 1828 1829
1830 1831 1832 1833 1834 1835 1836 1837 1838 1839
1840 1841 1842 1843 1844 1845 1846 1847 1848 1849
1850 1851 1852 1853 1854 1855 1856 1857 1858 1859
1860 1861 1862 1863 1864 1865 1866 1867 1868 1869
1870 1871 1872 1873 1874 1875 1876 1877 1878 1879
1880 1881 1882 1883 1884 1885 1886 1887 1888 1889
1890 1891 1892 1893 1894 1895 1896 1897 1898 1899

1900 1901 1902 1903 1904 1905 1906 1907 1908 1909
1910 1911 1912 1913 1914 1915 1916 1917 1918 1919
1920 1921 1922 1923 1924 1925 1926 1927 1928 1929
1930 1931 1932 1933 1934 1935 1936 1937 1938 1939
1940 1941 1942 1943 1944 1945 1946 1947 1948 1949
1950 1951 1952 1953 1954 1955 1956 1957 1958 1959
1960 1961 1962 1963 1964 1965 1966 1967 1968 1969
1970 1971 1972 1973 1974 1975 1976 1977 1978 1979
1980 1981 1982 1983 1984 1985 1986 1987 1988 1989
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009
2010 2011 2012 2013 2014 2015 2016 2017 2018 2019
2020 2021 2022 2023 2024 2025 2026 2027 2028 2029
2030 2031 2032 2033 2034 2035 2036 2037 2038 2039
2040 2041 2042 2043 2044 2045 2046 2047 2048 2049
2050 2051 2052 2053 2054 2055 2056 2057 2058 2059
2060 2061 2062 2063 2064 2065 2066 2067 2068 2069
2070 2071 2072 2073 2074 2075 2076 2077 2078 2079
2080 2081 2082 2083 2084 2085 2086 2087 2088 2089
2090 2091 2092 2093 2094 2095 2096 2097 2098 2099
E Henning
Last updated 11 November 2011.
Return to main calendar page.