Where is "Today" and "Yesterday" in Finder menu?
They don't appear to be there by default, but you can add them back in pretty easily.




Open a Finder window
Type "today" into the search box. 
It should offer you two options in a dropdown menu "Dates: today" and "Filenames - Name Matches: today". Pick the dates option.
The search should complete and the search bar should appear saying "This Mac" and the name of which ever folder the Finder window had opened. Choose "This Mac".
The search bar should also offer you a "Save" button. Click Save.
A Save panel should appear allowing you to specify a name and location for the saved search. There should also be a "Add To Sidebar" check box. Check the box.


Repeat for "Yesterday".