From RangeIndex to DatetimeIndex

I am analyzing the time series of an action (historical from 2000 to 2018)

df.index
Out[179]: RangeIndex(start=0, stop=4309, step=1)

df.info
[4309 rows x 5 columns]>

type(df)
Out[178]: pandas.core.frame.DataFrame

I want to be able to better manage my time series, placing all data of the DatetimeIndex type to be able to make a more punctual analysis (monthly, quarterly, etc.) How can I do it? Can it be?