> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sdf.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Time Functions

## `current_time`

*Supported Signatures*

```sql theme={null}
function current_time() returns time
function current_time(time_zone string) returns time
```

[🔗 Official Documentation](https://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators#current_time)

## `format_time`

*Supported Signatures*

```sql theme={null}
function format_time(string, time) returns string
```

[🔗 Official Documentation](https://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators#format_time)

## `parse_time`

*Supported Signatures*

```sql theme={null}
function parse_time(string, string) returns time
```

[🔗 Official Documentation](https://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators#parse_time)

## `time`

*Supported Signatures*

```sql theme={null}
function time(int64, int64, int64) returns time
function time(timestamp) returns time
function time(timestamp, time_zone string) returns time
function time(datetime) returns time
```

[🔗 Official Documentation](https://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators#time)

## `time_add`

*Supported Signatures*

```sql theme={null}
function time_add(time, interval microsecond to hour) returns time
```

[🔗 Official Documentation](https://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators#time_add)

## `time_diff`

*Supported Signatures*

```sql theme={null}
function time_diff(time, time, date_time_part string) returns bigint
	where date_time_part in (microsecond, millisecond, second, minute, hour)
```

[🔗 Official Documentation](https://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators#time_diff)

## `time_sub`

*Supported Signatures*

```sql theme={null}
function time_sub(time, interval microsecond to hour) returns time
```

[🔗 Official Documentation](https://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators#time_sub)

## `time_trunc`

*Supported Signatures*

```sql theme={null}
function time_trunc(time, time_part string) returns time
	where time_part in (microsecond, millisecond, second, minute, hour)
```

[🔗 Official Documentation](https://cloud.google.com/bigquery/docs/reference/standard-sql/functions-and-operators#time_trunc)