The New Moon phase is defined to be the moment when the moon is almost directly between the Earth and the Sun. At this moment the moon's dark surface faces the Earth. The New Moon is therefore completely invisible. The date and time of this invisible New Moon is commonly found in almanacs, newspapers and calendars.
The Islamic month begins with the visible First Crescent and not with the invisible New Moon. The first Crescent is usually sighted in the western sky just after sunset on the first or second evening after the New Moon phase. The sighting depends on the age of the crescent, the time difference between sunset and moonset and the angular distance between the sun and the moon.
We should not confuse the New Moon with the visible thin crescent. We should realise that a crescent following a lunar month of 30 days will look larger and stay longer than the crescent following a month of 29 days.
The first date of the month is proved in the following way:
- If a person sights the moon himself.
- If a person confirms he has sighted the moon, and his words assure or satisfy another person as well as everything else assuring or satisfying him.
- If two just (Adil) persons say that they have sighted the moon, the first date of the month will not be proved if they differ about the particulars (i.e. particular details as to how it was sighted).
- If 30 days pass from the 1st of the moon of Shaaban whereby the 1st of Ramadhan is proved and if 30 days pass from the 1st of Ramadhan whereby the 1st of Shawaal is proved.
If the moon is high up in the sky or sets late, it is not proof of the fact that it appeared the previous night. However, if the moon is seen before noon, that day will be treated as the 1st of the month (i.e. it will be assumed that the new moon appeared the previous night). Similarly if there is a halo (crown of light) around it, it goes to show that the new moon appeared the previous night.