Resample hourly TimeSeries with certain starting hour

2021 Update: base is deprecated since version 1.1.0: The new arguments that you should use are ‘offset’ or ‘origin’.

df.resample('24H',
 origin=datetime(2012,1,1,17) # <--  ADD THIS
).sum() 

New in version 1.1.0

origin{‘epoch’, ‘start’, ‘start_day’}, Timestamp or str, default ‘start_day’ The timestamp on which to adjust the grouping. The timezone of origin must match the timezone of the index. If a timestamp is not used, these values are also supported:

• ‘epoch’: origin is 1970-01-01
• ‘start’: origin is the first value of the timeseries
• ‘start_day’: origin is the first day at midnight of the timeseries

2020 Update: for dataframes

Use the base keyword as referred in the doc:

Code example:

df.resample(pd.Timedelta('24 hours'), # or '24H'
 base=17 # <--  ADD THIS
).sum() 

Resample has an base argument which covers this case:

ts.resample(rule='24H', closed='left', label='left', base=17).sum()

Output:

2012-01-01 17:00:00    24
2012-01-02 17:00:00    24
2012-01-03 17:00:00    12
Freq: 24H