计算工作日，包括oracle SQL中没有日历表的日期之间的假期

Okay, so I've done quite a lot of reading on the possibility of emulating the networkdays function of excel in sql, and have come to the conclusion that by far the easiest solution is to have a calendar table which will flag working days or non working days. However, due to circumstances out of my control, we don't have access to such a luxury and it's unlikely that we will any time in the near future. Okay, so I've done quite a lot of reading on th