Issue 1:
Code Sample, a copy-pastable example if possible

In [147]: pandas.Timestamp('4 pm')
---------------------------------------------------------------------------
OutOfBoundsDatetime Traceback (most recent call last)
<ipython-input-147-333a3814fcab> in <module>()
----> 1 pandas.Timestamp('4 pm')

pandas/tslib.pyx in pandas.tslib.Timestamp.__new__ (pandas/tslib.c:10447)()

pandas/tslib.pyx in pandas.tslib.convert_to_tsobject (pandas/tslib.c:27555)()

pandas/tslib.pyx in pandas.tslib.convert_str_to_tsobject (pandas/tslib.c:29955)()

pandas/tslib.pyx in pandas.tslib.convert_to_tsobject (pandas/tslib.c:28700)()

pandas/tslib.pyx in pandas.tslib._check_dts_bounds (pandas/tslib.c:32835)()

OutOfBoundsDatetime: Out of bounds nanosecond timestamp: 1-01-01 16:00:00

Problem description

this type of string conversion doesn't work with 0.19.2 since upgrade from 0.16.0

traced the problem using git bisect to this commit:

c2ea0d4

Expected Output

In [3]: pandas.Timestamp('4 pm')

Out[3]: Timestamp('2017-04-20 16:00:00')

Output of pd.show_versions()

INSTALLED VERSIONS
------------------
commit: None
python: 2.7.6.final.0
python-bits: 64
OS: Linux
OS-release: 3.13.0-112-generic
machine: x86_64
processor: x86_64
byteorder: little
LC_ALL: None
LANG: en_US.UTF-8
LOCALE: None.None

pandas: 0.19.2

nose: None

pip: 9.0.1

setuptools: 34.3.3

Cython: None

numpy: 1.11.2

scipy: None

statsmodels: None

xarray: None

IPython: 5.3.0

sphinx: None

patsy: None

dateutil: 2.5.3

pytz: 2016.7

blosc: None

bottleneck: None

tables: None

numexpr: None

matplotlib: None

openpyxl: None

xlrd: None

xlwt: None

xlsxwriter: None

lxml: None

bs4: None

html5lib: None

httplib2: None

apiclient: None

sqlalchemy: None

pymysql: None

psycopg2: None

jinja2: None

boto: None

pandas_datareader: None

Issue 2:
I assume that this was officially supported before. Haven't narrowed it down any more than sometime between 0.16.2 and 0.17.0.

In [1]: pd.__version__
Out[1]: '0.16.2'

In [2]: pd.date_range("Jan 1", "March 31", name="date")
Out[2]:
DatetimeIndex(['2015-01-01', '2015-01-02', '2015-01-03', '2015-01-04',
'2015-01-05', '2015-01-06', '2015-01-07', '2015-01-08',
'2015-01-09', '2015-01-10', '2015-01-11', '2015-01-12',
...

In [1]: pd.__version__
Out[1]: '0.17.0'

In [2]: pd.date_range("Jan 1", "March 31", name="date")
---------------------------------------------------------------------------
OutOfBoundsDatetime Traceback (most recent call last)
<ipython-input-2-8eaca08051ac> in <module>()
----> 1 pd.date_range("Jan 1", "March 31", name="date")

/Users/tom.augspurger/Envs/py3/lib/python3.5/site-packages/pandas/tseries/index.py in date_range(start, end, periods, freq, tz, normalize, name, closed)
1912 return DatetimeIndex(start=start, end=end, periods=periods,
1913 freq=freq, tz=tz, normalize=normalize, name=name,
-> 1914 closed=closed)
1915
1916

/Users/tom.augspurger/Envs/py3/lib/python3.5/site-packages/pandas/util/decorators.py in wrapper(*args, **kwargs)
87 else:
88 kwargs[new_arg_name] = new_arg_value
---> 89 return func(*args, **kwargs)
90 return wrapper
91 return _deprecate_kwarg

/Users/tom.augspurger/Envs/py3/lib/python3.5/site-packages/pandas/tseries/index.py in __new__(cls, data, freq, start, end, periods, copy, name, tz, verify_integrity, normalize, closed, ambiguous, dtype, **kwargs)
234 return cls._generate(start, end, periods, name, freq,
235 tz=tz, normalize=normalize, closed=closed,
--> 236 ambiguous=ambiguous)
237
238 if not isinstance(data, (np.ndarray, Index, ABCSeries)):

/Users/tom.augspurger/Envs/py3/lib/python3.5/site-packages/pandas/tseries/index.py in _generate(cls, start, end, periods, name, offset, tz, normalize, ambiguous, closed)
383
384 if start is not None:
--> 385 start = Timestamp(start)
386
387 if end is not None:

pandas/tslib.pyx in pandas.tslib.Timestamp.__new__ (pandas/tslib.c:8967)()

pandas/tslib.pyx in pandas.tslib.convert_to_tsobject (pandas/tslib.c:22303)()

pandas/tslib.pyx in pandas.tslib.convert_str_to_tsobject (pandas/tslib.c:24364)()

pandas/tslib.pyx in pandas.tslib.convert_to_tsobject (pandas/tslib.c:23344)()

pandas/tslib.pyx in pandas.tslib._check_dts_bounds (pandas/tslib.c:26590)()

OutOfBoundsDatetime: Out of bounds nanosecond timestamp: 1-01-01 00:00:00