Last week Marian missed a couple days because of a cold/cough/et al. Today her supervisor was concerned that Marian didn't call in, so she decided to call Marian. Marian answered and said she's fine, but doesn't work today. (She works four 10 hour days). Her supervisor was embarrassed.
Which reminds me of a story when I worked @ the branch. One of the liberrians, Mike, had a long career in social work. He was super concerned one Tuesday when Frank didn't come into work. Mike was sure Frank had a heart attack. He immediately told lots of stories of how he's seen this happen before... and when he called he found out that Frank wouldn't be in b/c he worked the previous Sunday!