API field
Timestamps
One label per interval, at the start of the interval
Unit ISO datetimes, interval start
What it is
The date and time of every interval in ISO 8601 form, at the fixed UTC offset given by the time zone, at the start of the interval. The intervals must be evenly spaced and increasing. As an alternative, give a start time and a step and leave this list empty.
Typical values and how to get it
Hourly files carry 8,760 labels from midnight on 1 January, 8,784 in a leap year. Sub-hourly files need a step that divides a day, such as 10, 15 or 30 minutes. In a request the labels must mark interval starts. The upload parser shifts the end-of-interval labels it recognises back by one step and says so in its report: TMY3 files, labels that run to 24:00, files marked as end-of-period, and hourly files whose first label is 01:00. A file without a date column is read by its row count from midnight on 1 January: 8,760 or 8,784 rows hourly, 17,520 or 17,568 at 30 minutes, 35,040 or 35,136 at 15 minutes, 52,560 or 52,704 at 10 minutes, 105,120 or 105,408 at 5 minutes.
References
- Wilcox & Marion 2008, Users Manual for TMY3 Data Sets, NREL/TP-581-43156
API
weather.timestamps