Today search smart folder criteria Screenshot for El Capitan? Tutorial?

Smart Folder search criteria for : today :

Screenshots are normally saved to your Desktop.

You cannot add a Smart Folder to the sidebar, once it has been removed.

Reproduce your search, and on saving, add it to your sidebar.

Smart Folders are saved here : /Users/"your user name"/Library/Saved Searches,

unless you toggled "Where:" when saving, and chose another location.

Follow this link :

OS X El Capitan: Create or modify a Smart Folder

Sorry, I should have explained how to add the "Any of the following are true" to the Smart Folder search criteria :

Add a layer clicking on the plus button :

Press the Option key, the plus sign will change to a horizontal ellipsis :

Click on the horizontal ellipsis, and the "Any of the following are true" layer will be added to your search criteria,

there may be a layer above this, which you can remove.

&

When searching for a Script :

Use "kind:script" (without the quotation marks) in your Finder search field :

You can use Spotlight to find an item created, or modified on a specific date :

Or, just use date:

The date format you use to search, will depend on the date format used in your System Preferences.

May I add one more thing to balsa2 fine explanation?

I was trying to set up a Smart Folder that would trawl my Mac including email names and contents for a specific search string.

Found I couldn't do it via the Smart Folder search set up.

However as Spotlight can be told to trawl emails too, as balsa2 said, I did a search first in Spotlight then from the results chose option to "Show in Finder Window". This window can be saved as a Smart Folder and will continue to search through emails. docs, filenames the lot.

I mention this because I have read elsewhere that by default Finder search ignores emails. This I guess is a work around.