Remove reference in OS to date and time functions

Since they moved to Time

doc/classes/OS.xml

@@ -4,7 +4,7 @@
 		Operating System functions.
 	</brief_description>
 	<description>
-		Operating System functions. OS wraps the most common functionality to communicate with the host operating system, such as the clipboard, video driver, date and time, timers, environment variables, execution of binaries, command line, etc.
+		Operating System functions. OS wraps the most common functionality to communicate with the host operating system, such as the clipboard, video driver, delays, environment variables, execution of binaries, command line, etc.
 	</description>
 	<tutorials>
 		<link title="OS Test Demo">https://godotengine.org/asset-library/asset/677</link>