Align dates in rustup toolchains with those in rustc -V

promote-release/src/main.rs

@@ -44,7 +44,12 @@ fn main() {
         release: env::args().nth(2).unwrap(),
         secrets: t!(secrets.parse()),
         handle: Easy::new(),
-        date: output(Command::new("date").arg("+%Y-%m-%d")).trim().to_string(),
+	// For Nightly, this is running soon after midnight
+	// so the date of 10 minutes ago is yesterday,
+	// which likely matches the commit date of the latest commit on the master branch:
+	// https://github.com/rust-lang/rust-central-station/pull/27
+        date: output(Command::new("date").arg("--date=10 minutes ago").arg("+%Y-%m-%d"))
+	    .trim().to_string(),
         current_version: None,
     }.run()
 }