Python Pandas - Return the Period object as a timestamp with monthly frequency

To return the Period object as a timestamp with monthly frequency, use the period.to_timestamp() method and set the freq parameter as 'M'.

Understanding Period Objects

The pandas.Period represents a period of time. When you convert it to a timestamp with monthly frequency, it aligns to the month-end by default ?

import pandas as pd

# Creating a Period object with second frequency
period = pd.Period(freq="S", year=2021, month=9, day=18, hour=17, minute=20, second=45)

# Display the Period object
print("Period...\n", period)

# Convert to timestamp with monthly frequency
print("\nPeriod to Timestamp with monthly (month-end) frequency...\n", 
      period.to_timestamp(freq='M'))

Period...
 2021-09-18 17:20:45

Period to Timestamp with monthly (month-end) frequency...
 2021-09-30 00:00:00

Different Monthly Frequencies

You can use different monthly frequency aliases to control the alignment ?

import pandas as pd

period = pd.Period(freq="D", year=2021, month=9, day=18)
print("Original Period:", period)

# Month-end frequency
print("Month-end (M):", period.to_timestamp(freq='M'))

# Month-start frequency  
print("Month-start (MS):", period.to_timestamp(freq='MS'))

Original Period: 2021-09-18
Month-end (M): 2021-09-30 00:00:00
Month-start (MS): 2021-09-01 00:00:00

Key Points

• The to_timestamp() method converts Period objects to Timestamp objects
• Using freq='M' aligns the timestamp to month-end
• Using freq='MS' aligns the timestamp to month-start
• The resulting timestamp always has time components set to 00:00:00

Conclusion

Use period.to_timestamp(freq='M') to convert Period objects to month-end timestamps. This is useful for time series analysis when you need consistent monthly alignment.