Date time label on time independent data files

[dkang2]

Using VERDI to display time independent (or one time step) data files, such as daily/monthly sum files, the data time label under the tile plot doesn't reflect the date time label from the file. Even though it is time independent, it still has one datetime label, such as Times = "2023-08-01_00:00:00" ; in the example file /work/MOD3DEV/dkj/Verdi/example_files/WWLLN_12US1_Total_20230801.nc

When display the data, VERDI shows the current datetime, not the file datetime (see the image below). It would be nice for VERDI to display the file datetime if it exists.