In pandas, I can create a TimedeltaIndex array using for example:

```
pd.timedelta_range(0,periods=9,freq="2H30T")
```

In the code above, `freq="2H30T"` gives us the period's interval of 2 hours and 30 minutes.

Its output will be the following:

```
TimedeltaIndex(['00:00:00', '02:30:00', '05:00:00', '07:30:00', '10:00:00',
                '12:30:00', '15:00:00', '17:30:00', '20:00:00'],
               dtype='timedelta64[ns]', freq='150T')
```

So, I tried to play with the [pandas time strings list](https://pandas.pydata.org/pandas-docs/stable/user_guide/timeseries.html#offset-aliases).


I wanted to define the period's interval as 2 years and 5 months, and using the time string list above, I came up with 
```
pd.timedelta_range(0,periods=9,freq="2A5M")
```

However, this doesn't work, and outpours the following error message: 
`ValueError: Invalid frequency: 2A5M`. 
I've also tried 2Y5M, and similarly got an error message.