The RTA has announced the timings for the Dubai Metro for Ramadan 2019 as follows:
Metro Stations on the Red Line will be operating from Saturday to Wednesday from 05:00 am to 00:00 (midnight). On Thursday from 05:00 am to 01:00 am (of the following day), and on Friday from 10:00 am to 01:00 am (of the following day).
The Metro Stations on the Green Line will be operating from Saturday to Wednesday from 05:30 am to 00:00 (midnight). On Thursday from 05:30 am to 01:00 am (of the following day), and on Friday from 10:00 am to 01:00 am (of the following day).
These timings are actually the same as the standard timings for the Dubai Metro at other times of the year.
Ramadan 2019 in Dubai is likely to run from Sunday May 5th to Tuesday June 4th, although final dates will be confirmed nearer the time corresponding to the sighting of the moon.