content/shared/influxql-v3-reference/functions/date-time.md
Use InfluxQL date and time functions to perform time-related operations.
Returns the current system time (UTC).
Supported only in the WHERE clause.
now()
Used in the GROUP BY clause
to group data into time-based intervals, also known as "windows", using the specified interval.
Timestamps in the time column are updated to the start boundary of the window
they're in and grouped by time.
Windows use preset round-number boundaries based on the specified interval that
are independent of time conditions in the
WHERE clause.
This operation can be used to do the following:
Supported only in the GROUP BY clause.
time(interval[, offset])
0s.{{< expand-wrapper >}}
{{% expand "Downsample data into time-based intervals" %}}
The following example uses the Bitcoin price sample dataset.
SELECT
MEAN(price)
FROM bitcoin
WHERE
code = 'GBP'
AND time >= '2023-05-01T00:00:00Z'
AND time < '2023-05-15T00:00:00Z'
GROUP BY time(2d)
{{% influxql/table-meta %}} name: bitcoin {{% /influxql/table-meta %}}
| time | mean |
|---|---|
| 2023-05-01T00:00:00Z | 23680.120447159094 |
| 2023-05-03T00:00:00Z | 24048.71484033149 |
| 2023-05-05T00:00:00Z | 24461.9194901099 |
| 2023-05-07T00:00:00Z | 23796.43801933702 |
| 2023-05-09T00:00:00Z | 23118.709889285707 |
| 2023-05-11T00:00:00Z | 22465.008364444446 |
| 2023-05-13T00:00:00Z | 22499.464763186803 |
{{% /expand %}} {{< /expand-wrapper >}}
Applies a timezone offset to timestamps in query results. Offsets include any seasonal offset such as Daylight Savings Time (DST) or British Summer Time (BST). Supported only in the time zone clause.
tz(time_zone)
{{< expand-wrapper >}}
{{% expand "Return the UTC offset for Chicago's time zone" %}}
The following example uses the Home sensor sample dataset.
{{% influxdb/custom-timestamps %}}
SELECT *
FROM home
WHERE
room = 'Kitchen'
AND time >= '2022-01-01T08:00:00Z'
AND time <= '2022-01-01T12:00:00Z'
tz('America/Chicago')
{{% influxql/table-meta %}} name: home {{% /influxql/table-meta %}}
| time | co | hum | room | temp |
|---|---|---|---|---|
| 2022-01-01T02:00:00-06:00 | 0 | 35.9 | Kitchen | 21 |
| 2022-01-01T03:00:00-06:00 | 0 | 36.2 | Kitchen | 23 |
| 2022-01-01T04:00:00-06:00 | 0 | 36.1 | Kitchen | 22.7 |
| 2022-01-01T05:00:00-06:00 | 0 | 36 | Kitchen | 22.4 |
| 2022-01-01T06:00:00-06:00 | 0 | 36 | Kitchen | 22.5 |
{{% /influxdb/custom-timestamps %}} {{% /expand %}} {{< /expand-wrapper >}}