Fix retrieval of timestamp

byPeriodSlice.php

@@ -75,7 +75,7 @@ $summary = [];
 
 foreach ($messages as $message) {
 	$sender = trim($xpath->evaluate('substring-before(substring-after(normalize-space(div[@class = "hidden-xs"]/following-sibling::text()[1]), "By "), " · #")', $message), '"');
-	$timestamp = $xpath->evaluate('substring-before(substring-after(.//script[@class = "timedisp"], "DisplayShortTime( "), " ,")', $message);
+	$timestamp = $xpath->evaluate('substring-before(substring-after(.//script[@class = "timedisp"], "DisplayShortTime("), ",")', $message);
 
 	$date = new DateTime(null, $tz);
 	$date->setTimestamp($timestamp / 1000000000);