This tweet might be of interest: https://twitter.com/arnicas/status/333958442404421632

Vincent and Bearcart both have had JSON serialization failures on certain platforms because of it. This has been my solution for bearcart: 

```python
            if pd.isnull(value):
                return None
            elif (isinstance(value, pd.tslib.Timestamp) or
                  isinstance(value, pd.Period)):
                return time.mktime(value.timetuple())
            elif isinstance(value, (int, np.integer)):
                return int(value)
            elif isinstance(value, (float, np.float_)):
                return float(value)
            elif isinstance(value, str):
                return str(value)
            else:
                return value
```