When printing a weekly calendar the days of the week are not printed on the page. They disappear going from eMClient to print preview.
I think it has something to do with the space available. If you select to print only work days, so reduce it from 7 columns to 5 or 6, then it kinda works, but looks untidy because some letters go to the next line.
But if you change the page to landscape, with only work days, it works.
You will find the setting for printing workdays by clicking on the settings cog: