Reference time

Hourly values in Meteonorm are designated by the end time of the interval. For instance, a value provided for 14:00 represents the average (or sum, in the case of precipitation) for the interval from 13:00 to 14:00. The midpoint of this interval is 13:30.

To enhance clarity and avoid confusion, our API explicitly includes both start_time and end_time for each interval. If a specific format provides only a single timestamp, it refers to the end time of the interval, unless the format's definition explicitly states otherwise.

Results are provided in local time, excluding daylight saving time.

The equation of time is based on Dogniaux (1975), and the formulae for solar trajectories are taken from the European Solar Atlas (ESRA, 2000).