Develop UTC

Hi @nperez

The time zone has been changed from local to UTC. I used the following scripts to test. Please let me know if you find any problems, thanks!

# Case 1
pobs <- paste0('/esarchive/recon/ecmwf/era5/monthly_mean/',
               '$VAR_NAME$_f1h/$VAR_NAME$_$YEAR$$MONTH$.nc')

data <- Load(var = 'sfcWind',
             obs = list(list(path = pobs)),
             sdates = '20181101',
             leadtimemin = 1, leadtimemax = 1,
             output = 'lonlat',
             grid = 'r360x181',
             method = 'conservative',
             storefreq = 'monthly',
             latmin = 10, latmax = 20,
             lonmin = 0, lonmax = 10)
data$Dates

# Case 2
data <- Load('prlr', exp = 'system5c3s',
                     obs = 'era5',
                     sdates = c('20100501'),# '20110501', '20120501'),
                     #leadtimemin = 121, leadtimemax = 151,
                     latmin = 44, latmax = 47,
                     lonmin = 5, lonmax = 9,
                     nmember = 1,
                     storefreq = "daily", sampleperiod = 1,
                     output = "lonlat")
data$Dates

Cheers,
An-Chi