Maybe not the most concise title, but it's a great feature. Have you ever needed to fill a column or row with dates, but skip weekends? Pain isn't it?
Well no. There's a hidden menu that enables this. Put your first date in your first cell. Now hover over the bottom right corner of that cell until your cursor becomes a "+". Right-click (yes, right-click) and drag, either to the right to fill the row or down to fill the column. When you've gone as far as you think you need to, release the mouse button and you'll be presented with a nice little menu. This allows you to fill the range with all days (standard behaviour), weekdays only, months (giving the same day of each month) or years (the same day each year).
Clicking the Series option even allows you to only include every nth value, combined with the above.
It's a lovely feature, but I question its placement. Hiding things like this only causes frustration for those users who've done it the hard way for the last umpteen years.
