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Date & Time (Timestamp)

A Date & Time (Timestamp) variable is a way to specify a particular moment in time. You can use it to show the current time or a specific point in the past or future.

Specification

  • A Date & Time variable is represented as an RFC 3339 string using the date-time profile.
  • It does include offset information.
  • We highly recommend to use UTC time as this ensures consistent time handling across different regions, avoids timezone-related bugs, and simplifies data synchronization between services.

Examples​

Date & Time StringDescriptionOffset
2020-12-24T14:30:00Z

2:30 pm on December 24, 2020 in Coordinated Universal Time

UTC
2020-12-24T15:30:00+01:00

3:30 pm on December 24, 2020 e.g. in Central European Time

UTC+01:00

Did You Notice?

Both timestamps in this table represent the exact same moment in time, just expressed using different offsets. One speaks UTC, the other UTC+1, but they're pointing to the same cosmic event. Ain't that nice?

Additional Metadata​

Troubleshooting​

Ensure Correct Date and Time Settings on All Devices

Juggling with dates and time can be a real pain, especially in a client-server architecture with multiple computers being involved.

So, make sure all the computers involved are set up correctly:

  1. Backends (aka your PLC)
    • The time on the PLC must be set correctly, including the time zone in which the system clock is running.
    • Timestamps from the PLC must always include an offset specification (e.g. UTC or UTC+2).
  2. Computers Executing the HELIO Runtime
    • The time on the computer that is executing the HELIO Runtime must be set correctly as well.
  3. Computers Executing the HMIs
    • Finally the time zone on all the computers running the HMI in the browser must be set correctly.

Learn More​

Why is there an offset between the timestamps from my PLC and those displayed on the HMI?