Definition
A time series is a sequence of values with timestamps - consumption per hour, temperature per minute, voltage per second. What separates them from ordinary tables is that time carries meaning: a gap is information, a value arriving twice is a problem, and a value arriving late for a period already calculated triggers work. In the energy sector this is complicated by time not being unambiguous. The daylight-saving transition gives one day of 23 hours and one of 25, and a series storing local time without a zone gets two hours that look identical in autumn and one missing in spring. Metering dataData from electricity meters - the foundation for billing, balance settlement and market processes in the power market. is therefore normally stored in UTC and displayed in local time - a distinction easy to overlook until the one night a year when it is not.