OED has an entry on bi-, but not biweekly. It seems that usages of biweekly are technically correct.
Quote:
Originally Posted by OED
4. Lasting or continuing for two ; occurring or appearing every two ; as BIENNIAL, bi-hourly, bi-monthly, bi-weekly.
1843 in Proc. Amer. Philos. Soc. II. 247 *Bi-hourly observations..had ceased with the first of the present year.
1879 GLADSTONE in Daily News 1 Dec. 6/5 Annual as opposed to *bi-monthly or tri-monthly budgets.
b. Occurring or appearing twice in a ; as in bi-diurnal, bi-monthly, bi-quarterly, bi-weekly, bi-winter, bi-yearly. (The ambiguous usage is confusing, and might be avoided by the use of semi-; e.g. semi-monthly, semi-weekly; cf. half-yearly.)
1854 WOODWARD Mollusca (1856) 32 A *bi-diurnal visit from the tide.
1878 Print. Trades Jrnl. xxv. 4 A new Spanish *bi-monthly journal.
1884 Pall Mall G. 15 Feb. 16 To issue these etchings in *bi-quarterly numbers.
1885 FARRAR Camb. Bible Sch. Luke xviii. 12 The *bi-weekly fast of the Pharisees..The days chosen were Thursday and Monday.
1884 Harper's Mag. Feb. 394/1 The mail-carriers are making one of their *bi-winter trips.
1879 Print. Trades Jrnl. XXVIII. 9 A *bi-yearly calendar.
d. The adjs. are also used substantively: bi-weekly, a newspaper, magazine, etc., published once every two weeks.
1890 in WEBSTER. 1978 Daily Tel. 2 Dec. 1/7 The remainder are weeklies, bi-weeklies and three provincial Sunday newspapers.
1843 in Proc. Amer. Philos. Soc. II. 247 *Bi-hourly observations..had ceased with the first of the present year.
1879 GLADSTONE in Daily News 1 Dec. 6/5 Annual as opposed to *bi-monthly or tri-monthly budgets.
b. Occurring or appearing twice in a ; as in bi-diurnal, bi-monthly, bi-quarterly, bi-weekly, bi-winter, bi-yearly. (The ambiguous usage is confusing, and might be avoided by the use of semi-; e.g. semi-monthly, semi-weekly; cf. half-yearly.)
1854 WOODWARD Mollusca (1856) 32 A *bi-diurnal visit from the tide.
1878 Print. Trades Jrnl. xxv. 4 A new Spanish *bi-monthly journal.
1884 Pall Mall G. 15 Feb. 16 To issue these etchings in *bi-quarterly numbers.
1885 FARRAR Camb. Bible Sch. Luke xviii. 12 The *bi-weekly fast of the Pharisees..The days chosen were Thursday and Monday.
1884 Harper's Mag. Feb. 394/1 The mail-carriers are making one of their *bi-winter trips.
1879 Print. Trades Jrnl. XXVIII. 9 A *bi-yearly calendar.
d. The adjs. are also used substantively: bi-weekly, a newspaper, magazine, etc., published once every two weeks.
1890 in WEBSTER. 1978 Daily Tel. 2 Dec. 1/7 The remainder are weeklies, bi-weeklies and three provincial Sunday newspapers.
