Bryan Fields, a Costco employee in Baltimore and member of Teamsters Local 570, told ABC News that the strike deadline comes after months of stalled conversations, extensions and failed negotiations with the company.

The strike authorization vote passed with an 85% margin, the union said. Investors didn’t seem concerned, however. Costco stock was up 1% to $952.28 in midmorning trading Tuesda

The unionized Costco workers are on a contract that expires Jan. 31, according to their Teamsters representatives.