Premobl seeks to obtain 24 hours’ worth of meteorology data for a source for each day, which is necessary for generating emission factors. However, the definition of a “day” differs for sources in different time zones. By default, Premobl uses each source’s time zone to determine a day for that time zone. To instead use the same day-start-time for all sources, the UNIFORM_STIME environment variable can be used.

If the inventory covers multiple time zones, all sources will not have the same coverage of days. Premobl will use meteorology data from previous or subsequent days to fill in missing data. If appropriate data are not available, the program will quit with an error and you must provide additional meteorology data to cover the time period of interest. Currently, Premobl does not considers Daylight Saving time in its determination of “day”.