Pandas apply algorithm on sliding time window

Question

I have a dataframe with a timestamp column, and I have to create a new column based on the result of an algorithm. The algorithm has to be applied on the current row, and all previous and following rows that have the timestamp inside a fixed interval. So if for example the time interval is 1 hour, I need to choose all the rows that are at maximum 1h before or 1h after the "current" row, apply the algorithm and save the result in the new column, and do this for all the rows
df['new_column'] = algorithm(df[df['timestamp'] inside time window])
What I don't know is how to get the portion of dataframe that is inside the time window