I have a weird date format in some files I'm parsing. Here are some examples:

```
1954203
2012320
2010270

```

The first four digits are the year and the next three digits are day of year. For example, the first date is the 203rd day of 1954, or 7/22/1954.

My questions are:

1. What's this date format called?
2. Is there a pre-canned way to parse it? I don't want to reinvent the wheel here.

Edit: Sorry, I forgot to mention my language. PHP.