Welcoming Ramzan

According to some Ulema, the desire to see the Ramzan Moon is sunnah. According to others, it is wajib. Therefore, when anyone should see the Ramzan moon, should face the Qibla and raise the hands toward the sky and recite the following dua :

Rabbi wa rabbukal-lahu rabbul aalameen Allahuma ahil-lahu alaina bil amni wal imaani Was-salamati was-salami walmusaraeti ila ma tuhibbu wa tardha Allahumma barik lana fee shahrina haza warzuqna khairahu Wa aonahu wasrif anna dhar-rahu wa shar-rahu wa balaa-ahu wa fitnatahu

My Lord and your Lord is Allah, the Lord of the worlds. O Allah for us let this month be a period of peace, faith, safety and total submission to Thy will; make us walk apace swiftly to that which Thou likes and approves. O Allah pour out much blessings on us in this month, make available for us its generous good and assistance, and keep us safe from the harm, evil, misfortune and mischief that may try to trap us in this month.

And the best dua to recite after viewing the moon is Dua-e-Sahifa-e-Kamila.

Another dua after viewing the Ramzan Moon

Prophet Mohammad(pbuh&hf) used to recite this dua after sighting the Ramzan moon while facing the Qibla:

Allahumma ahil-lahu alaina bil-amni wal imaani was-salamati wal islami wal aafiyatil majal-lalati wa difa-il asqaami wal aoni alas-salati was-siyami wal qayami wa tilawatil Qurani Allahumma sal-limna le shahri ramazana wa tasal-lamhu minna wa sal-limna fihe hatta yanqaziya anna shahru ramadhana wa qad afaota wa ghafarta lana wa rahimtana