Series astype() doesn't convert int64 to datetime64 using M8[D] anymore

add units='D' to Timestamp/to_datetime epoch support

I have an int64 series representing days since epoch which I’d like to convert to datetime64. This works in 11.0 but raises an exception in 0.11.1.dev-964516a. The exception message is “TypeError: cannot convert datetimelike to dtype [datetime64[D]]”.

import pandas as pd
s = pd.Series([0,1,2])
print s.astype('M8[D]')

My workaround is:

import pandas as pd
s = pd.Series([0,1,2])
print pd.Series(s.values.astype('M8[D]'))

[jreback]

this is on purpose, try this for converting from epoch (the docs for this are not fully merged yet):

I have never seen anyone specify epoch as you have an mean Days…what is the use case (most epcoh is seconds, but usually ms)

In [6]: Series(pd.to_datetime([0,1,2],unit='s'))
Out[6]: 
0   1970-01-01 00:00:00
1   1970-01-01 00:00:01
2   1970-01-01 00:00:02
dtype: datetime64[ns]

I guess could add unit=D as well

In [25]: pd.to_datetime(pd.Series([0,1,2])*86400,unit='s')
Out[25]: 
0   1970-01-01 00:00:00
1   1970-01-02 00:00:00
2   1970-01-03 00:00:00
dtype: datetime64[ns]

[jreback]

closed via #3973