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  * __
  * [ pandas.DatetimeIndex ](pandas.DatetimeIndex.html)
  * pandas.Datet... 

#  pandas.DatetimeIndex.is_month_start  #

_ property  _ DatetimeIndex.  is_month_start  [ [source]
](https://github.com/pandas-
dev/pandas/blob/v2.2.2/pandas/core/indexes/extension.py#L67-L75) #

    

Indicates whether the date is the first day of the month.

Returns  :

    

Series or array

    

For Series, returns a Series with boolean values. For DatetimeIndex, returns a
boolean array.

See also

` is_month_start  `

    

Return a boolean indicating whether the date is the first day of the month.

[ ` is_month_end  `
](pandas.DatetimeIndex.is_month_end.html#pandas.DatetimeIndex.is_month_end
"pandas.DatetimeIndex.is_month_end")

    

Return a boolean indicating whether the date is the last day of the month.

Examples

This method is available on Series with datetime values under the ` .dt  `
accessor, and directly on DatetimeIndex.

    
    
    >>> s = pd.Series(pd.date_range("2018-02-27", periods=3))
    >>> s
    0   2018-02-27
    1   2018-02-28
    2   2018-03-01
    dtype: datetime64[ns]
    >>> s.dt.is_month_start
    0    False
    1    False
    2    True
    dtype: bool
    >>> s.dt.is_mo