DatetimeIndex.is_month_start Pandas DatetimeIndex.is_month_start returns an empty array containing boolean values ​​corresponding to each entry in a DatetimeIndex object. The value is set to True if the date is the first day of the month. Otherwise, the function returns False indicating that the date is not the first day of the month.

Syntax: DatetimeIndex.is_month_start

Return: numpy array containing logical values.

Example # 1: Use the DatetimeIndex.is_month_start attribute to check if the dates present in the DatetimeIndex are the first day of the month.

Output:

Now we want to find out if the dates contained in this DatetimeIndex are the first day of the month.

Output:

As we can see in the output, the function returned an empty array containing boolean values ​​for each entry in the DatetimeIndex object.  True values ​​indicate that the corresponding date was the first day of the month, and False values ​​indicate that the corresponding date was not the first day of the month.

Example # 2: Use the DatetimeIndex.is_month_start attribute to check if the dates present in the DatetimeIndex object are the first day of the month.

Output:

Now we want to find out if the dates contained in this the DatetimeIndex object, the first day of the month.

Exit:

As we can see in the output, the function returned an empty array containing boolean values ​​for each entry in the DatetimeIndex object.  True values ​​indicate that the corresponding date was the first day of the month, and False values ​​indicate that the corresponding date was not the first day of the month.