After completing the 29 days of Ramdhan the Muslims look for the moon of Shawwal. If they see the moon/crescent of Shawwal they celebrate the Eid ul fitr on the next day. If they don't see the Moon/Crescent they will keep the fasting for next day and after completing 30 days they celebrate Eid.
Eid ul fitr in following countries is expected to be on 15 June 2018.
and in many other countries.
The moon is technically 0.9% to 1.1 % in these regions and it is expected that the moon of this size is visible to human naked eye.
We wish you a happy Eid Mubarak.