
Reciting Kammavaca
from Upāli Thein, Bagan, Myanmar
Most sources are in agreement this year, but the Sri Lankan calendar from the Galdua group of Forest Monasteries (marked SL below), only makes the extra day adjustment (adhikavāra) on the 3rd Uposatha in Gimhāna, and is therefore one day in front till that time. There are also some small differences in the Dhammayut calendar, marked by DY below.
Uposatha Calendar 2013 in PDF format

to calculate monastic dawn and midday anywhere in the world
and get a full year chart for your area see this page
Myanmar: Burmese Classic
Thailand (Mahānikai) Forest Sangha Publications
Thailand (Dhammayut) (DY) Access to Insight
Sri Lanka (Galdua) (SL): Uposatha Calendar sent to me from Na-Uyana