dateStart

Learn how to use the dateStart function in Notion formulas.

The `dateStart()` function returns the start date from a date range. It accepts a single date argument.

``````dateStart(date)

date.dateStart()
```Code language: JavaScript (javascript)```

`dateStart()` is useful for obtaining the start date from a Date property which contains a date range.

When you pass a single date as the argument – i.e. from a Created Time/Last Edited Time property, or a timestamp – `dateStart()` simply returns that date.

``````/* Assume a property "Date" exists, with a row value of June 23, 2022 → June 27, 2022 */
dateStart(prop("Date")) /* Output: June 23, 2022 */
```Code language: JavaScript (javascript)```

It’s useful to note that date math functions like dateAdd and dateSubtract return a date object that does not contain a date range – even if their argument does include one.

When these functions are passed a date object that includes a range, they only use a start date.

For this reason, the following two formulas will return the exact same date:

``````/* Assume a property "Date" exists, with a row value of June 23, 2022 → June 27, 2022 */
start(dateAdd(prop("Date"),30,"days")) /* Output: July 23, 2022 */

end(dateAdd(prop("Date"),30,"days")) /* Output: July 23, 2022 */
```Code language: JavaScript (javascript)```

Therefore, you must use the dateEnd function within your date math function if you wish to operate on the end date in a date range:

``````/* Assume a property "Date" exists, with a row value of June 23, 2022 → June 27, 2022 */
dateAdd(dateEnd(prop("Date")), 30, "days") /* Output: July 27, 2022 */
```Code language: JavaScript (javascript)```

The example database below counts the number of days in a date range.

``````dateBetween(
dateEnd(
prop("Date Range")
),
dateStart(
prop("Date Range")
),
"days"
)
```Code language: JavaScript (javascript)```

This example formula uses `dateStart()` and dateEnd to pass beginning and ending arguments to the dateBetween function.

By specifying “days” as the third argument, we get the number of days in the date range.