# OPENINGBALANCEMONTH

Evaluates the **expression** at the first date of the month in the current context.

## Syntax

```
OPENINGBALANCEMONTH(<expression>,<dates>[,<filter>])
```

### Parameters

Term | Definition |
---|---|

expression | An expression that returns a scalar value. |

dates | A column that contains dates. |

filter | (optional) An expression that specifies a filter to apply to the current context. |

## Return value

A scalar value that represents the **expression** evaluated at the first date of the month in the current context.

## Remarks

The

**dates**argument can be any of the following:- A reference to a date/time column.
- A table expression that returns a single column of date/time values.
- A Boolean expression that defines a single-column table of date/time values.

Constraints on Boolean expressions are described in the topic, CALCULATE function.

The

**filter**expression has restrictions described in the topic, CALCULATE function.This function is not supported for use in DirectQuery mode when used in calculated columns or row-level security (RLS) rules.

## Example

The following sample formula creates a measure that calculates the 'Month Start Inventory Value' of the product inventory.

```
= OPENINGBALANCEMONTH(SUMX(ProductInventory,ProductInventory[UnitCost]*ProductInventory[UnitsBalance]),DateTime[DateKey])
```

## See also

OPENINGBALANCEYEAR function

OPENINGBALANCEQUARTER function

Time intelligence functions

CLOSINGBALANCEMONTH function