Trying to find the actual syntax for the TIME specification in alerts.cfg

So something like TIME=*:1200:2100 only sends that alerts during that time, 7 days a week. I assume the * is for day of the week. So if you only wanted to send it Monday - Friday, what is the syntax for it? Is it like cron where I can put 1-5 in there like TIME=1-5:1200:2100 or am I totally off base?

Thanks in advance.