Manipulate timestamps with Flux

    If you’re just getting started with Flux queries, check out the following:

    • to discover a variety of ways to run your queries.

    Use the time() function to convert a to an RFC3339 timestamp.

    RFC3339 to Unix nanosecond

    Use the uint() function to convert an RFC3339 timestamp to a Unix nanosecond timestamp.

    2. // Returns 1568808000000000000

    Flux doesn’t support mathematical operations using values. To calculate the duration between two timestamps:

    1. Use the uint() function to convert each timestamp to a Unix nanosecond timestamp.
    2. Subtract one Unix nanosecond timestamp from the other.
    3. Use the duration() function to convert the result into a duration.
    1. time1 = uint(v: 2019-09-17T21:12:05Z)
    2. time2 = uint(v: 2019-09-18T22:16:35Z)
    4. duration(v: time2 - time1)
    5. // Returns 25h4m30s

    Flux doesn’t support duration column types. To store a duration in a column, use the string() function to convert the duration to a string.

    now() is cached at runtime, so all instances of now() in a Flux script return the same value.

    Current system time

    Import the package and use the system.time() function to return the current system time of the host machine in RFC3339 format.

    1. import "system"
    3. system.time()

    system.time() returns the time it is executed, so each instance of system.time() in a Flux script returns a unique value.

    To normalize irregular timestamps, truncate all _time values to a specified unit with the . This is useful in join() and operations where points should align by time, but timestamps vary slightly.

    1.     |> truncateTimeColumn(unit: 1m)

    Input:

    _time_value
    2020-01-01T00:00:00Z2.0
    2020-01-01T00:01:00Z1.9
    2020-01-01T00:03:00Z1.8
    2020-01-01T00:04:00Z1.9
    2020-01-01T00:05:00Z2.1

    The experimental.addDuration() function adds a duration to a specified time and returns the resulting time.

    By using experimental.addDuration(), you accept the .

    Subtract a duration from a timestamp

    The subtracts a duration from a specified time and returns the resulting time.

    By using experimental.subDuration(), you accept the risks of experimental functions.

    3. experimental.subDuration(d: 6h, from: 2019-09-16T12:00:00Z)
    5. // Returns 2019-09-16T06:00:00.000000000Z

    The function adds the specified duration of time to each value in time columns (_start, _stop, _time).

    1. from(bucket: "example-bucket")
    2.     |> range(start: -5m)
    3.     |> timeShift(duration: 12h)

    Shift backward in time: