Using pd.Series.dt.end_time creates different timestamps than it should

Question

Consider a series of datetimes

s = pd.Series(pd.to_datetime(['2010-08-05']))
s

0   2010-08-05
dtype: datetime64[ns]

I want to create a series of period objects and get an attribute end_time.

sp = s.dt.to_period('M')
sp

0   2010-08
dtype: object

Now I am accessing the attribute end_time.

sp.dt.end_time

0   2010-08-31
dtype: datetime64[ns]

I was almost satisfied until I realized what end_timeshould be Timestamp('2010-08-31 23:59:59.999999999'), notTimestamp('2010-08-31 00:00:00')

Ok so i compared

sp.iloc[0].end_time

Timestamp('2010-08-31 23:59:59.999999999')

---

sp.dt.end_time.iloc[0]

Timestamp('2010-08-31 00:00:00')

---

sp.iloc[0].end_time == sp.dt.end_time.iloc[0]

False

---

It makes no sense to me. Clearly, the periods are correct. How can I get pd.Series.dt.end_timeto return the right thing?