np.where acting up while comparing time in pandas

I have the following code:

np.where((final_df_SDC['Start Time']>= final_df_SDC['Repayment_Time']) & (final_df_SDC['End Time'] <= final_df_SDC['Repayment_Time']),"OCC","-")

which is giving me error : TypeError: '>=' not supported between instances of 'datetime.time' and 'str'

However, when I am checking dtypes

final_df_SDC['Start Time'].dtype
final_df_SDC['Repayment_Time'].dtype
final_df_SDC['End Time'].dtype

I get : dtype('O')

Then how is it not comparing?
I tried converting to pd.datetime(final_df_SDC['Start Time']) then it said TypeError: <class 'datetime.time'> is not convertible to datetime
I am highly confused now. How do I let all these time values compare with each other?

Sample values : 08:55:18 in this format for all three columns.

SAMPLE VALUES after I converted to astype(str)

Start Time  End Time    Repayment_Time
5415    2021-12-01 15:12:24 2021-12-01 15:12:48 2021-12-01 17:41:20
5482    2021-12-01 15:17:05 2021-12-01 15:18:32 2021-12-01 16:33:49
5539    2021-12-01 15:19:40 2021-12-01 15:19:42 2021-12-01 20:02:20
6011    2021-12-01 15:46:18 2021-12-01 15:47:50 2021-12-01 15:51:01
6128    2021-12-01 15:54:20 2021-12-01 15:57:28 2021-12-01 16:00:51
6177    2021-12-01 15:55:44 2021-12-01 15:56:07 2021-12-01 20:00:34
6262    2021-12-01 15:58:28 2021-12-01 15:58:39 2021-12-01 12:11:2

>Solution :

For all columns use to_datetime with convert to strings:

s = pd.to_datetime(final_df_SDC['Start Time'].astype(str))
e = pd.to_datetime(final_df_SDC['End Time'].astype(str))
r = pd.to_datetime(final_df_SDC['Repayment_TimeTime'].astype(str))

Or to_timedelta:

s = pd.to_timedelta(final_df_SDC['Start Time'].astype(str))
e = pd.to_timedelta(final_df_SDC['End Time'].astype(str))
r = pd.to_timedelta(final_df_SDC['Repayment_TimeTime'].astype(str))

Then change <= with >= like:

np.where((s <= r) & (e >= r),"OCC","-")

Or use Series.between:

np.where(r.between(s, e),"OCC","-")