Green’s Dictionary of Slang

a week; thus skew, weeks.

1859		Hotten Dict. of Modern Sl. etc. 127: KEW, a week. KEWS, or skew, weeks.
1864, 1867, 1870		Hotten Sl. Dict.
1873		Sl. Dict.
1882		Sydney Sl. Dict. (2 edn) 11: Kews, Skew, or Skeeu - Weeks.
1909		J. Ware Passing Eng. of the Victorian Era.