People around the world will celebrate Eid al-Fitr on different days this year, depending on when the new moon is seen.
Some countries have already started celebrations on Thursday, others will celebrate on Friday, and a few are likely to wait until Saturday.
Afghanistan, Niger and Mali said they saw the new moon on Wednesday evening. That means Eid began there on Thursday 19 March.
Most countries in the Middle East and parts of Africa will celebrate Eid on Friday 20 March.
Authorities in places like Saudi Arabia and the United Arab Emirates said they did not see the moon on Wednesday, so Ramadan will last the full 30 days.
Countries marking Eid on Friday include Saudi Arabia, the UAE, Qatar, Kuwait, Bahrain and Oman.
Others include Palestine, Lebanon, Jordan, Iraq (Sunni), Yemen, Egypt, Sudan, Nigeria and Senegal.
Australia has also confirmed Friday, based on astronomical calculations.
In some places, people are still waiting to see if the moon will appear on Thursday evening.
In Morocco, officials are observing the sky. If the moon is seen, Eid will be on Friday. If not, it will be on Saturday 21 March.
India, Pakistan and Bangladesh are also checking for the moon. Early signs suggest they may celebrate on Saturday, but this has not been officially confirmed yet.
Singapore has already said Eid will be on Saturday 21 March because the moon will not be visible earlier.
