I need to run a cronjob every 14 days on a friday i. e. every second friday. Following is the closest I can think of:
0 10 */14 * 5
I think crontab would run this cronjob at 10:00 on the 14th and 28th day of a month (and that's not even every 14 days!) if this day is a friday. This condition would not be met every second friday, of course.