-Pohela Boishakh - The most widely celebrated secular national festival of the country. Here people from all walks of life participate in various cultural shows called Boishakhi Mela,wearing national dress (kurta or Shari), eating sweets and wishing every one happy new year.
-Ekushey - National Mother Language Day - February 21. This day marks the anniversary of the martyrs that died in 1952 while protesting the imposition of Urdu, in the name of Islam, as the mother-tongue. The uprisings to support Bangla as the mother language fueled the movement towards secular nationalism that culminated in independence in 1971. The holiday is marked by (one of the most colourful events in Asia) tributes to the martyrs by political leaders, intellectuals, poets, writers, artisans and singing beginning at one minute after midnight on the 21st. Government offices are closed, and expect traffic disruption from February 20.
-Independence day - March 26th- On this day 'Father of the Nation' Bangabandhu Sheikh Mujibur Rahman proclaimed country's independence.
-Victory day - December 16th- On this day Pakistani occupied forces surrendered to joint Bangladeshi & Indian forces.
-Eid-ul-Fitr - the largest Muslim holiday of the year, it celebrates the end of the holy month of Ramazan. Food is the highlight, and if you're lucky you'll be invited into a private home for a feast. Businesses close for at least a couple days if not a week.
-Eid-ul-Azha - is the second largest Muslim festival.
-Durga Puja - Four days around October. The largest Hindu festival in the country, it goes on for several days with festivities varying each day.
-Christmas - December 25th, This is the largest Festival of Christian Community in the country which is declared as a goverment holiday. A prayer is held at Tejgaon Church at 11 PM (Local Time) in 24th December. Also some other churches in Dhaka also arrange prayer at 24th December.

Ramadan dates
-2011 (1432): Aug 1 - Aug 29
-2012 (1433): Jul 20 - Aug 18
-2013 (1434): Jul 9 - Aug 7
The festival of Eid ul-Fitr is held after the end of Ramadan and may last several days. Exact dates depend on astronomical observations and may vary from country to country.