How do I get slack to remind me every fortnight from next Saturday

I was trying to do this today also. Either of these options work:

• Needs to be run the week before you want it to start:

  /remind me to "ABC" every other Saturday 8pm
  /remind me to "ABC" Saturday 8pm every 2 weeks
  

• Otherwise specify the start date

  /remind me to "ABC" Jun 19th 8pm every 2 weeks
  /remind me to "ABC" next Saturday 8pm every 2 weeks
  

Slackbot told me:

I will remind you to “ABC” at 8PM every other Saturday (next occurrence is June 19th).