# DATE\$1TRUNC function
<a name="DATE_TRUNC"></a>

The DATE\$1TRUNC function truncates a timestamp expression or literal based on the date part that you specify, such as hour, day, or month. 

## Syntax
<a name="DATE_TRUNC-synopsis"></a>

```
date_trunc(format, datetime) 
```

## Arguments
<a name="DATE_TRUNC-arguments"></a>

 *format*   
The format representing the unit to be truncated to. Valid formats are as follows:   
+ "YEAR", "YYYY", "YY" - truncate to the first date of the year that the ts falls in, the time part will be zero out
+ "QUARTER" - truncate to the first date of the quarter that the ts falls in, the time part will be zero out
+ "MONTH", "MM", "MON" - truncate to the first date of the month that the ts falls in, the time part will be zero out
+ "WEEK" - truncate to the Monday of the week that the ts falls in, the time part will be zero out
+ "DAY", "DD" - zero out the time part
+ "HOUR" - zero out the minute and second with fraction part
+ "MINUTE"- zero out the second with fraction part
+ "SECOND" - zero out the second fraction part
+ "MILLISECOND" - zero out the microseconds
+ "MICROSECOND" - everything remains

 *ts*   
A datetime value

## Return type
<a name="DATE_TRUNC-return-type"></a>

Returns timestamp *ts* truncated to the unit specified by the format model

## Examples
<a name="DATE_TRUNC-example"></a>

The following example truncates a date value to the beginning of the year. The output shows that the date "2015-03-05" has been truncated to "2015-01-01", which is the beginning of the year 2015.

```
SELECT date_trunc('YEAR', '2015-03-05');
 
 date_trunc
-----------
2015-01-01
```