The new moon of Ramadhan is special to Muslims. It announces the start of the holy month and the beginning of the blessings and mercy associated with Ramadhan. According to the Holy Prophet (s) whoever sees the new moon of Ramadhan should recite the following Du'a.1
In the name of Allah the Beneficent the Merciful.
My Lord and your Lord is Allah,
Lord of the worlds
O Allah let the new moon bring us,
peace and faith
safety and submission
and a hastening towards what you like
and are pleased with.
O Allah bless us in this month of ours,
and give us of its good,
and its assistance
Keep us away from its harm,
and its evil,
its difficulties,
and its trials.
Allah has decreed that Muslims use the movement of the moon to determine the passing of months and years. When the early Muslims were asked about the new moon, Allah revealed a verse saying:
يسئلونك عن الأهلة قُل هى مواقيت للناس والحج
They ask you concerning the new moons. Say; they are times appointed for (the benefit of) people, and (for) pilgrimage. (2:189)
بسم الله الرحمن الرحيم
ربي وربُك الله
رب العالمين
اللهم اهله علينا بالأمن والإيمان
والسلامة والإسلام
والمُسارعة إلى ما تُحب وترضى
اللهم بارك لنا في شهرنا هذا وارزقنا خيره وعونه
واصرف عنا ضره وشره
وبلائه وفتنته
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1. This Du'a is highly beneficial, and may be read at the beginning of every lunar month. (Translator)
source : rafed.net