Biweekly vs Semiweekly

Let’s settle this.

biweekly
Means every other week. Semiweekly means twice a week.

AP Stylebook (paid subscription required)

It’s no ISO standard, but it’ll do.

References

• CBS News: Let’s (try to) end the debate: Does biweekly mean twice a week or twice a month?
• Grammarbook.com: Bi vs. Semi (weekly, monthly, annually)
• LA Times: A Word, Please: Whatever seems right to you
• Merriam-Webster: biweekly
• Merriam-Webster: On ‘Biweekly’ and ‘Bimonthly’