Pandas Timestamp(year=2011, month=8, day=1) returns last day of month

Question

Wanted to create a time range from August 1, 2011 dynamically to the last month of the existing data. Don't know why I'm returning time series with the last day of the month instead of the first.

Any suggestions? Please ignore my petty comments to my coworkers.

# Our Formatting System is garbage - So Have to code it to non garbage
    start_date = pd.Timestamp(2011, 8, 1,)
    months = pd.date_range(start_date, periods=len(timeseries[0]), freq='M')
    print(months)

Answer 1

By using the freq M , you are telling it to use month's end. See this link for a description of datetime offsets in pandas, but in short M is

month end frequency

Use 'MS' (month start) instead:

>>> start_date = pd.Timestamp(2011, 8, 1,)
>>> months = pd.date_range(start_date, periods=10, freq='MS')
>>> print(months)
DatetimeIndex(['2011-08-01', '2011-09-01', '2011-10-01', '2011-11-01',
               '2011-12-01', '2012-01-01', '2012-02-01', '2012-03-01',
               '2012-04-01', '2012-05-01'],
              dtype='datetime64[ns]', freq='MS')