The ampersand (&) symbol represents the concatenation operator. You can use it to join strings:
- Q: "now" & "then"
- A: nowthen
and to create time ranges:
- Q: now & day
- A: Mon, 04 Apr 2016 22:13:27 +0200 to Tue, 05 Apr 2016 22:13:27 +0200
While in the first example
"now" represents a string, because it is enclosed in double quotes,
in the second example
now is a relevance keyword that you can use to extract the current time and
date from the system clock.