# Write a Pandas program to generate sequences of fixed-frequency dates and time spans.  
 import pandas as pd
dtr = pd.date_range('2018-01-01', periods=12, freq='H')
print("Hourly frequency:")
print(dtr)
dtr = pd.date_range('2018-01-01', periods=12, freq='min')
print("\nMinutely frequency:")
print(dtr)
dtr = pd.date_range('2018-01-01', periods=12, freq='S')
print("\nSecondly frequency:")
print(dtr)
dtr = pd.date_range('2018-01-01', periods=12, freq='2H')
print("nMultiple Hourly frequency:")
print(dtr)
dtr = pd.date_range('2018-01-01', periods=12, freq='5min')
print("\nMultiple Minutely frequency:")
print(dtr)
dtr = pd.date_range('2018-01-01', periods=12, freq='BQ')
print("\nMultiple Secondly frequency:")
print(dtr)
dtr = pd.date_range('2018-01-01', periods=12, freq='w')
print("\nWeekly frequency:")
print(dtr)
dtr = pd.date_range('2018-01-01', periods=12, freq='2h20min')
print("\nCombine together day and intraday offsets-1:")
print(dtr)
dtr = pd.date_range('2018-01-01', periods=12, freq='1D10U')
print("\nCombine together day and intraday offsets-2:")
print(dtr)
