Dua said when the new moon is sighted

I think there may be some confusion here!

In Islamic tradition, the start of the new month (also known as the "hijri" calendar) is determined by the sighting of the crescent moon. This is based on the hadith (a saying or action of the Prophet Muhammad) that states:

"When you see the crescent, complete the month, and when you see it, break your fast." (Bukhari and Muslim)

According to this hadith, the new month begins when the crescent moon is sighted, and the previous month is completed. This means that the exact date of the new month is determined by the sighting of the crescent moon, which can vary depending on the location and weather conditions.

In practice, this means that the start of the new month is announced by the sighting of the crescent moon by a reliable observer, usually a moon-sighting committee or a local imam. The announcement is then disseminated to the community, and the new month begins.

So, to answer your question, Dua (prayer) is not said when the new moon is sighted, but rather the new month begins when the crescent moon is sighted, and the community celebrates the start of the new month with prayer and other rituals.