((اللَّهُ أَكْبَرُ، اللَّهُمَّ أَهِلَّهُ عَلَيْنَا بِالْأَمْنِ وَالْإِيمَانِ، وَالسَّلاَمَةِ وَالْإِسْلاَمِ، وَالتَّوْفِيقِ لِمَا تُحِبُّ رَبَّنَا وَتَرْضَى، رَبُّنَا وَرَبُّكَ اللَّهُ)).
Transliteration
(Allahu akbar, allahumma ahillahu AAalayna bil-amni wal-eeman, wassalamati wal-islam, wattawfeeiqi lima tuhibbu watarda, rabbuna warabbukal-lah.)
Translation
(Allah is the greatest. O Allah, let the crescent loom above us in safety, faith, peace, and Islam, and in agreement with all that You love and pleases You. Our Lord and your Lord is Allah.)
Source
Hisnul Muslim (Fortress of the Muslim), No. 175 — chapter “Invocation for sighting the new moon”. hisnmuslim.com
Related Duas
Invocations for when the wind blows
Supplication 1 of 2
((اللَّهُمَّ إِنِّي أَسْــــــأَلُكَ خَيْرَهَا، وَأَعُوذُ بِكَ مِنْ شَرِّهَا)).
(O Allah, I ask You for it’s goodness and I take refuge with You from it’s evil.)
Hisnul Muslim · No. 166
((سُبْحَانَ الَّذِي يُسَبِّحُ الرَّعْدُ بِحَمْدِهِ وَالْمَلاَئِكةُ مِنْ خِيفَتِهِ)).
(How perfect He is, (The One) Whom the thunder declares His perfection with His praise, as do the angles out of fear of Him.)
Hisnul Muslim · No. 168
Some invocations for rain
Supplication 1 of 3
((اللَّهُمَّ اسْقِنَا غَيْثاً مُغِيثاً مَرِيئاً مَرِيعاً، نَافِعاً غَيْرَ ضَارٍّ، عَاجِلاً غَيْرَ آجِلٍ)).
(O Allah, send upon us helpful, wholesome and healthy rain, beneficial not harmful rain, now, not later.)
Hisnul Muslim · No. 169