My bot asks for a user's birthday which is returned as a timex. It's not clear that there are any functions in Composer to convert this to a datetime.

So, after asking for a date, the bot returns a timex into user.dob

```
[{
"value": "1989-02-01",
"timex": "1989-02-01"
}]

```

I've tried using the getProperty built-in function as in:

```
@{getProperty(user.dob,'value')}

```

but this returns as null. Likewise using 'timex'. Any suggestions?