What is "clockwatching"

Usage examples of "clockwatching".

I haven’t felt so edgy since school days, what with the physical discomfort, anxious clockwatching, drugs screwing up my hormones .

But times had changed under the Rads, and now even Whitechapel had its tightlaced scrubfaced women and its cakey clockwatching men, who read the 'Dictionary of Useful Knowledge' and the 'Journal of Moral Improvement', and looked to get ahead.