diff --git a/calendar/setup/tz_aliases.inc.php b/calendar/setup/tz_aliases.inc.php
index a8c6a651bb..7b595297f5 100644
--- a/calendar/setup/tz_aliases.inc.php
+++ b/calendar/setup/tz_aliases.inc.php
@@ -19,6 +19,7 @@ $tz_aliases = array(
 	'Argentina Standard Time' => 'America/Argentina/Buenos_Aires',	// was 'America/Buenos_Aires',
 	'Armenian Standard Time' => 'Asia/Yerevan',
 	'Asia/Katmandu' => 'Asia/Kathmandu',
+	'Asia/Calcutta' => 'Asia/Kolkata',
 	'Atlantic Standard Time' => 'America/Halifax',
 	'Azerbaijan Standard Time' => 'Asia/Baku',
 	'Azores Standard Time' => 'Atlantic/Azores',
@@ -51,7 +52,7 @@ $tz_aliases = array(
 	'Greenland Standard Time' => 'America/Godthab',
 	'Greenwich Standard Time' => 'Atlantic/Reykjavik',	// was 'Africa/Reykjavik',
 	'Hawaiian Standard Time' => 'Pacific/Honolulu',
-	'India Standard Time' => 'Asia/Calcutta',
+	'India Standard Time' => 'Asia/Kolkata',
 	'Iran Standard Time' => 'Asia/Tehran',
 	'Israel Standard Time' => 'Asia/Jerusalem',
 	'Jordan Standard Time' => 'Asia/Amman',