API field
Time zone
The UTC offset of inline weather's timestamps, and the clock of the hourly answer
Unit h (UTC offset, standard time)
What it is
The UTC offset in hours, in standard time with no daylight-saving shift. Half-hour offsets are allowed. For weather sent inline it is the zone the timestamps are written in, which is usually the standard time of the site. A stored weather year (an upload or a typical year, sent as {"id": …}) keeps the zone it was stored in: the sun runs on that zone, and a different site.timezone puts the hourly series on its own clock. Each value moves by the difference, index 0 is 1 January 00:00 in site.timezone, and summary.warnings says so. The year's totals do not change.
Typical values and how to get it
Look it up for the location, or read it from the weather file header. TMY3 files are stamped in local standard time. NSRDB files state their UTC offset in the header, and the upload parser reads it. A file written in UTC needs 0. If not given: UTC+0. The weather upload takes the file's time zone, or the longitude divided by 15, rounded, when the file has none.
References
- Wilcox & Marion 2008, Users Manual for TMY3 Data Sets, NREL/TP-581-43156
- Sengupta, Xie, Lopez, Habte, Maclaurin & Shelby 2018, The National Solar Radiation Data Base (NSRDB), Renewable and Sustainable Energy Reviews 89 51–60
API
site.timezone