Pandas Series dt.is_month_start | Check if Date is First Day of Month
The dt.is_month_start attribute returns a boolean value indicating whether the date is the first day of the month.ExamplePython3 import pandas as pd sr = pd.Series(['2012-1-1', '2019-7-18 12:30', '2008-02-2 10:30', '2010-4-22 09:25', '2019-1-1 00:00']) idx = ['Day 1', 'Day 2', 'Day 3', 'Day 4', 'Day