C.R.S. § 24-70-102: Legal publications.

Every newspaper printed and published daily, or daily except Sundays and legal holidays, or on each of any five days in every week excepting legal holidays and including or excluding Sundays shall be considered and held to be a daily newspaper; every newspaper printed and published at regular intervals three times each week shall be considered and held to be a triweekly newspaper; every newspaper printed and published at regular intervals twice each week shall be considered and held to be a semiweekly newspaper; and every newspaper printed and published at regular intervals once each week shall be considered and held to be a weekly newspaper. No publication, no matter how frequently published, shall be considered a legal publication unless it has been admitted to the United States mails with periodicals mailing privileges.