0-7, because some people count funny, and the other people count funny too.

http://unixhelp.ed.ac.uk/CGI/man-cgi?crontab+5

```
   The time and date fields are:

	      field	     allowed values
	      -----	     --------------
	      minute	     0-59
	      hour	     0-23
	      day of month   1-31
	      month	     1-12 (or names, see below)
	      day of week    0-7 (0 or 7 is Sun, or use names)
```