Time in Utilitarian

One of the harder things to manage in AMR Operations is time. Especially when you are developing a solution that should be able to use many different kinds of meters in different regions under different regulatory rules.

An example of this is Sweden. For electricity meters the time of meters should be Swedish normal time, or Swedish time without day light savings times change. But for gas meter the gas day is counted from 06:00-06:00 in Swedish local time, with day light savings.

Timestamps

To make it possible to have meters that are in different timezones all timestamps in Utilitarian has a timezone attached to it. If the timezone isn't UTC it will be transformed to UTC upon saving.

Timezones.

In MeterDeviceConfig it is possible to set a timezone for a meter. If you want the meter to follow normal daylight savings rules for a timezone just use the normal one. Ex Europe/Stockholm. But if you need a meter in a zone that doesn't change at Daylight Savings Time (DST) you should use a constructed zone like Etc/GMT-2. To learn more about available timezones visit https://en.wikipedia.org/wiki/List_of_tz_database_time_zones

Warning

When using constructed zones, ex Etc/GMT-2 the sign of the hour is inverted from that of the ISO 8601 standard. So Etc/GMT-2 is 2 hours ahead of GMT. read more here...

Meter time

How the time is handled inside a meter device can be very different depending on manufacturer and protocol. Some meters have no knowledge of timezone, some have but have turned it off or some has detailed information about timezone and follow DST changes. We implement the time management in our execution environments and meter integrations according to the way the meter handles it internally.

Syncing time

When we want to sync time we do it against the servers internal clock and timezone UTC. When time needs to be corrected in a meter we convert the server time to the local time for the meters timezone and write it to the meter. This is run as an AmrTask and can be run on a schedule that suits the application.