# COLUMN\_PERIOD
The **COLUMN\_PERIOD** function returns the start or end date for the specified time period.
| | |
| ----- | ------------------------------------- |
| START | Returns the start date of the period. |
| END | Returns the end date of the period. |
## 1. COLUMN\_PERIOD.START
## Syntax
```javascript
COLUMN_PERIOD.START
```
## Return value
Based on the granularity, this function returns the first day of the month for the corresponding month, quarter, or year.
## Example
```javascript
COLUMN_PERIOD.START
//Returns the start date of the month, quarter, or year
```
Month level
Year level
Quarter level
## 2. COLUMN\_PERIOD.END
## Syntax
```javascript
COLUMN_PERIOD.END
```
## Return value
Returns the last day of the month for the corresponding month, quarter, or year, depending on the granularity.
## Example
```javascript
COLUMN_PERIOD.END
//Returns the end date for the month, quarter, or year
```
Year level
Quarter level
Month level
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