You asked for cron so only using cron you can do this using bash's date as a 2nd test:

0   0  8-14 *   *   [ "$(date '+%u')" = "3" ] && {your script}

• On every hour of days 8 through 14


• and then check for wednesday with bash's date. Daynumber 3 is wednesday

The comment from Soren A is a little wrong (BUT the man page is also wrong). 0 0 8-14 * WED = “At 00:00 on every day-of-month from 8 through 14 and on Wednesday.” From the last link:

Tip 1: If the day-of-month or day-of-week part starts with a *, they form an intersection. Otherwise they form a union. * * 3 * 1 runs on the 3rd day of the month and on Monday (union), whereas * * */2 * 1 runs on every second day of the month only if it's also a Monday (intersection). The manpage is incorrect about this detail. More info.