diff --git a/inc/tz/expand.php b/inc/tz/expand.php
index c5f5c1ba..89a8c215 100644
--- a/inc/tz/expand.php
+++ b/inc/tz/expand.php
@@ -46,6 +46,7 @@ define( 'DEBUG_EXPAND', false );
 * @param object $vResource is a VCALENDAR with a VTIMEZONE containing components needing expansion
 * @param object $range_start A RepeatRuleDateTime which is the beginning of the range for events.
 * @param object $range_end A RepeatRuleDateTime which is the end of the range for events.
+* @param int $offset_from The offset from UTC in seconds at the onset time.
 *
 * @return array of onset datetimes with UTC from/to offsets
 */
@@ -60,8 +61,6 @@ function expand_timezone_onsets( vCalendar $vResource, RepeatRuleDateTime $range
   $is_date = false;
   $has_repeats = false;
   $zone_tz = $vtz->GetPValue('TZID');
-  $range_start->setTimeZone($zone_tz);
-  $range_end->setTimeZone($zone_tz);
   
   foreach( $components AS $k => $comp ) {
     if ( DEBUG_EXPAND ) {
@@ -73,8 +72,14 @@ function expand_timezone_onsets( vCalendar $vResource, RepeatRuleDateTime $range
     }
     $dtstart_prop = $comp->GetProperty('DTSTART');
     if ( !isset($dtstart_prop) ) continue;
-    $dtstart_prop->SetParameterValue('TZID',$zone_tz);
     $dtstart = new RepeatRuleDateTime( $dtstart_prop );
+    $dtstart->setTimeZone('UTC');
+    $offset_from = $comp->GetPValue('TZOFFSETFROM');
+    $offset_from = (($offset_from / 100) * 3600) + ((abs($offset_from) % 100) * 60 * ($offset_from < 0 ? -1 : 0));
+    $offset_from *= -1;
+    $offset_from = "$offset_from seconds";
+    dbg_error_log( 'tz/update', "%s of offset\n", $offset_from);
+    $dtstart->modify($offset_from);
     $is_date = $dtstart->isDate();
     $instances[$dtstart->UTC('Y-m-d\TH:i:s\Z')] = $comp;
     $rrule = $comp->GetProperty('RRULE');
diff --git a/testing/tests/timezone/5040-expand.result b/testing/tests/timezone/5040-expand.result
index e70636e3..8565d293 100644
--- a/testing/tests/timezone/5040-expand.result
+++ b/testing/tests/timezone/5040-expand.result
@@ -12,133 +12,133 @@ Content-Type: application/xml; charset="utf-8"
   <calscale>Gregorian</calscale>
   <observance>
    <name>NZST</name>
-   <onset>2011-04-02T15:00:00Z</onset>
+   <onset>2011-04-03T14:00:00Z</onset>
    <utc-offset-from>+13:00</utc-offset-from>
    <utc-offset-to>+12:00</utc-offset-to>
   </observance>
   <observance>
    <name>NZDT</name>
-   <onset>2011-09-24T14:00:00Z</onset>
+   <onset>2011-09-25T14:00:00Z</onset>
    <utc-offset-from>+12:00</utc-offset-from>
    <utc-offset-to>+13:00</utc-offset-to>
   </observance>
   <observance>
    <name>NZST</name>
-   <onset>2012-03-31T15:00:00Z</onset>
+   <onset>2012-04-01T14:00:00Z</onset>
    <utc-offset-from>+13:00</utc-offset-from>
    <utc-offset-to>+12:00</utc-offset-to>
   </observance>
   <observance>
    <name>NZDT</name>
-   <onset>2012-09-29T14:00:00Z</onset>
+   <onset>2012-09-30T14:00:00Z</onset>
    <utc-offset-from>+12:00</utc-offset-from>
    <utc-offset-to>+13:00</utc-offset-to>
   </observance>
   <observance>
    <name>NZST</name>
-   <onset>2013-04-06T15:00:00Z</onset>
+   <onset>2013-04-07T14:00:00Z</onset>
    <utc-offset-from>+13:00</utc-offset-from>
    <utc-offset-to>+12:00</utc-offset-to>
   </observance>
   <observance>
    <name>NZDT</name>
-   <onset>2013-09-28T14:00:00Z</onset>
+   <onset>2013-09-29T14:00:00Z</onset>
    <utc-offset-from>+12:00</utc-offset-from>
    <utc-offset-to>+13:00</utc-offset-to>
   </observance>
   <observance>
    <name>NZST</name>
-   <onset>2014-04-05T15:00:00Z</onset>
+   <onset>2014-04-06T14:00:00Z</onset>
    <utc-offset-from>+13:00</utc-offset-from>
    <utc-offset-to>+12:00</utc-offset-to>
   </observance>
   <observance>
    <name>NZDT</name>
-   <onset>2014-09-27T14:00:00Z</onset>
+   <onset>2014-09-28T14:00:00Z</onset>
    <utc-offset-from>+12:00</utc-offset-from>
    <utc-offset-to>+13:00</utc-offset-to>
   </observance>
   <observance>
    <name>NZST</name>
-   <onset>2015-04-04T15:00:00Z</onset>
+   <onset>2015-04-05T14:00:00Z</onset>
    <utc-offset-from>+13:00</utc-offset-from>
    <utc-offset-to>+12:00</utc-offset-to>
   </observance>
   <observance>
    <name>NZDT</name>
-   <onset>2015-09-26T14:00:00Z</onset>
+   <onset>2015-09-27T14:00:00Z</onset>
    <utc-offset-from>+12:00</utc-offset-from>
    <utc-offset-to>+13:00</utc-offset-to>
   </observance>
   <observance>
    <name>NZST</name>
-   <onset>2016-04-02T15:00:00Z</onset>
+   <onset>2016-04-03T14:00:00Z</onset>
    <utc-offset-from>+13:00</utc-offset-from>
    <utc-offset-to>+12:00</utc-offset-to>
   </observance>
   <observance>
    <name>NZDT</name>
-   <onset>2016-09-24T14:00:00Z</onset>
+   <onset>2016-09-25T14:00:00Z</onset>
    <utc-offset-from>+12:00</utc-offset-from>
    <utc-offset-to>+13:00</utc-offset-to>
   </observance>
   <observance>
    <name>NZST</name>
-   <onset>2017-04-01T15:00:00Z</onset>
+   <onset>2017-04-02T14:00:00Z</onset>
    <utc-offset-from>+13:00</utc-offset-from>
    <utc-offset-to>+12:00</utc-offset-to>
   </observance>
   <observance>
    <name>NZDT</name>
-   <onset>2017-09-23T14:00:00Z</onset>
+   <onset>2017-09-24T14:00:00Z</onset>
    <utc-offset-from>+12:00</utc-offset-from>
    <utc-offset-to>+13:00</utc-offset-to>
   </observance>
   <observance>
    <name>NZST</name>
-   <onset>2018-03-31T15:00:00Z</onset>
+   <onset>2018-04-01T14:00:00Z</onset>
    <utc-offset-from>+13:00</utc-offset-from>
    <utc-offset-to>+12:00</utc-offset-to>
   </observance>
   <observance>
    <name>NZDT</name>
-   <onset>2018-09-29T14:00:00Z</onset>
+   <onset>2018-09-30T14:00:00Z</onset>
    <utc-offset-from>+12:00</utc-offset-from>
    <utc-offset-to>+13:00</utc-offset-to>
   </observance>
   <observance>
    <name>NZST</name>
-   <onset>2019-04-06T15:00:00Z</onset>
+   <onset>2019-04-07T14:00:00Z</onset>
    <utc-offset-from>+13:00</utc-offset-from>
    <utc-offset-to>+12:00</utc-offset-to>
   </observance>
   <observance>
    <name>NZDT</name>
-   <onset>2019-09-28T14:00:00Z</onset>
+   <onset>2019-09-29T14:00:00Z</onset>
    <utc-offset-from>+12:00</utc-offset-from>
    <utc-offset-to>+13:00</utc-offset-to>
   </observance>
   <observance>
    <name>NZST</name>
-   <onset>2020-04-04T15:00:00Z</onset>
+   <onset>2020-04-05T14:00:00Z</onset>
    <utc-offset-from>+13:00</utc-offset-from>
    <utc-offset-to>+12:00</utc-offset-to>
   </observance>
   <observance>
    <name>NZDT</name>
-   <onset>2020-09-26T14:00:00Z</onset>
+   <onset>2020-09-27T14:00:00Z</onset>
    <utc-offset-from>+12:00</utc-offset-from>
    <utc-offset-to>+13:00</utc-offset-to>
   </observance>
   <observance>
    <name>NZST</name>
-   <onset>2021-04-03T15:00:00Z</onset>
+   <onset>2021-04-04T14:00:00Z</onset>
    <utc-offset-from>+13:00</utc-offset-from>
    <utc-offset-to>+12:00</utc-offset-to>
   </observance>
   <observance>
    <name>NZDT</name>
-   <onset>2021-09-25T14:00:00Z</onset>
+   <onset>2021-09-26T14:00:00Z</onset>
    <utc-offset-from>+12:00</utc-offset-from>
    <utc-offset-to>+13:00</utc-offset-to>
   </observance>
diff --git a/testing/tests/timezone/5041-expand.result b/testing/tests/timezone/5041-expand.result
index a3298a14..b85119d5 100644
--- a/testing/tests/timezone/5041-expand.result
+++ b/testing/tests/timezone/5041-expand.result
@@ -18,7 +18,7 @@ Content-Type: application/xml; charset="utf-8"
   </observance>
   <observance>
    <name>EST</name>
-   <onset>2009-11-01T07:00:00Z</onset>
+   <onset>2009-11-01T06:00:00Z</onset>
    <utc-offset-from>-04:00</utc-offset-from>
    <utc-offset-to>-05:00</utc-offset-to>
   </observance>
@@ -30,7 +30,7 @@ Content-Type: application/xml; charset="utf-8"
   </observance>
   <observance>
    <name>EST</name>
-   <onset>2010-11-07T07:00:00Z</onset>
+   <onset>2010-11-07T06:00:00Z</onset>
    <utc-offset-from>-04:00</utc-offset-from>
    <utc-offset-to>-05:00</utc-offset-to>
   </observance>
@@ -42,7 +42,7 @@ Content-Type: application/xml; charset="utf-8"
   </observance>
   <observance>
    <name>EST</name>
-   <onset>2011-11-06T07:00:00Z</onset>
+   <onset>2011-11-06T06:00:00Z</onset>
    <utc-offset-from>-04:00</utc-offset-from>
    <utc-offset-to>-05:00</utc-offset-to>
   </observance>
@@ -54,7 +54,7 @@ Content-Type: application/xml; charset="utf-8"
   </observance>
   <observance>
    <name>EST</name>
-   <onset>2012-11-04T07:00:00Z</onset>
+   <onset>2012-11-04T06:00:00Z</onset>
    <utc-offset-from>-04:00</utc-offset-from>
    <utc-offset-to>-05:00</utc-offset-to>
   </observance>
@@ -66,7 +66,7 @@ Content-Type: application/xml; charset="utf-8"
   </observance>
   <observance>
    <name>EST</name>
-   <onset>2013-11-03T07:00:00Z</onset>
+   <onset>2013-11-03T06:00:00Z</onset>
    <utc-offset-from>-04:00</utc-offset-from>
    <utc-offset-to>-05:00</utc-offset-to>
   </observance>
@@ -78,7 +78,7 @@ Content-Type: application/xml; charset="utf-8"
   </observance>
   <observance>
    <name>EST</name>
-   <onset>2014-11-02T07:00:00Z</onset>
+   <onset>2014-11-02T06:00:00Z</onset>
    <utc-offset-from>-04:00</utc-offset-from>
    <utc-offset-to>-05:00</utc-offset-to>
   </observance>
@@ -90,7 +90,7 @@ Content-Type: application/xml; charset="utf-8"
   </observance>
   <observance>
    <name>EST</name>
-   <onset>2015-11-01T07:00:00Z</onset>
+   <onset>2015-11-01T06:00:00Z</onset>
    <utc-offset-from>-04:00</utc-offset-from>
    <utc-offset-to>-05:00</utc-offset-to>
   </observance>
@@ -102,7 +102,7 @@ Content-Type: application/xml; charset="utf-8"
   </observance>
   <observance>
    <name>EST</name>
-   <onset>2016-11-06T07:00:00Z</onset>
+   <onset>2016-11-06T06:00:00Z</onset>
    <utc-offset-from>-04:00</utc-offset-from>
    <utc-offset-to>-05:00</utc-offset-to>
   </observance>
@@ -114,7 +114,7 @@ Content-Type: application/xml; charset="utf-8"
   </observance>
   <observance>
    <name>EST</name>
-   <onset>2017-11-05T07:00:00Z</onset>
+   <onset>2017-11-05T06:00:00Z</onset>
    <utc-offset-from>-04:00</utc-offset-from>
    <utc-offset-to>-05:00</utc-offset-to>
   </observance>
@@ -126,7 +126,7 @@ Content-Type: application/xml; charset="utf-8"
   </observance>
   <observance>
    <name>EST</name>
-   <onset>2018-11-04T07:00:00Z</onset>
+   <onset>2018-11-04T06:00:00Z</onset>
    <utc-offset-from>-04:00</utc-offset-from>
    <utc-offset-to>-05:00</utc-offset-to>
   </observance>
@@ -138,7 +138,7 @@ Content-Type: application/xml; charset="utf-8"
   </observance>
   <observance>
    <name>EST</name>
-   <onset>2019-11-03T07:00:00Z</onset>
+   <onset>2019-11-03T06:00:00Z</onset>
    <utc-offset-from>-04:00</utc-offset-from>
    <utc-offset-to>-05:00</utc-offset-to>
   </observance>
@@ -150,7 +150,7 @@ Content-Type: application/xml; charset="utf-8"
   </observance>
   <observance>
    <name>EST</name>
-   <onset>2020-11-01T07:00:00Z</onset>
+   <onset>2020-11-01T06:00:00Z</onset>
    <utc-offset-from>-04:00</utc-offset-from>
    <utc-offset-to>-05:00</utc-offset-to>
   </observance>
@@ -162,7 +162,7 @@ Content-Type: application/xml; charset="utf-8"
   </observance>
   <observance>
    <name>EST</name>
-   <onset>2021-11-07T07:00:00Z</onset>
+   <onset>2021-11-07T06:00:00Z</onset>
    <utc-offset-from>-04:00</utc-offset-from>
    <utc-offset-to>-05:00</utc-offset-to>
   </observance>
diff --git a/testing/tests/timezone/5042-expand.result b/testing/tests/timezone/5042-expand.result
index 8156f1a9..af9c6c8b 100644
--- a/testing/tests/timezone/5042-expand.result
+++ b/testing/tests/timezone/5042-expand.result
@@ -18,7 +18,7 @@ Content-Type: application/xml; charset="utf-8"
   </observance>
   <observance>
    <name>EST</name>
-   <onset>2011-11-06T07:00:00Z</onset>
+   <onset>2011-11-06T06:00:00Z</onset>
    <utc-offset-from>-04:00</utc-offset-from>
    <utc-offset-to>-05:00</utc-offset-to>
   </observance>
@@ -30,7 +30,7 @@ Content-Type: application/xml; charset="utf-8"
   </observance>
   <observance>
    <name>EST</name>
-   <onset>2012-11-04T07:00:00Z</onset>
+   <onset>2012-11-04T06:00:00Z</onset>
    <utc-offset-from>-04:00</utc-offset-from>
    <utc-offset-to>-05:00</utc-offset-to>
   </observance>
diff --git a/testing/tests/timezone/5043-expand.result b/testing/tests/timezone/5043-expand.result
index 70e5e037..6cf071da 100644
--- a/testing/tests/timezone/5043-expand.result
+++ b/testing/tests/timezone/5043-expand.result
@@ -18,7 +18,7 @@ Content-Type: application/xml; charset="utf-8"
   </observance>
   <observance>
    <name>EST</name>
-   <onset>2014-11-02T07:00:00Z</onset>
+   <onset>2014-11-02T06:00:00Z</onset>
    <utc-offset-from>-04:00</utc-offset-from>
    <utc-offset-to>-05:00</utc-offset-to>
   </observance>
@@ -30,7 +30,7 @@ Content-Type: application/xml; charset="utf-8"
   </observance>
   <observance>
    <name>EST</name>
-   <onset>2015-11-01T07:00:00Z</onset>
+   <onset>2015-11-01T06:00:00Z</onset>
    <utc-offset-from>-04:00</utc-offset-from>
    <utc-offset-to>-05:00</utc-offset-to>
   </observance>
@@ -42,7 +42,7 @@ Content-Type: application/xml; charset="utf-8"
   </observance>
   <observance>
    <name>EST</name>
-   <onset>2016-11-06T07:00:00Z</onset>
+   <onset>2016-11-06T06:00:00Z</onset>
    <utc-offset-from>-04:00</utc-offset-from>
    <utc-offset-to>-05:00</utc-offset-to>
   </observance>
@@ -54,7 +54,7 @@ Content-Type: application/xml; charset="utf-8"
   </observance>
   <observance>
    <name>EST</name>
-   <onset>2017-11-05T07:00:00Z</onset>
+   <onset>2017-11-05T06:00:00Z</onset>
    <utc-offset-from>-04:00</utc-offset-from>
    <utc-offset-to>-05:00</utc-offset-to>
   </observance>
@@ -66,7 +66,7 @@ Content-Type: application/xml; charset="utf-8"
   </observance>
   <observance>
    <name>EST</name>
-   <onset>2018-11-04T07:00:00Z</onset>
+   <onset>2018-11-04T06:00:00Z</onset>
    <utc-offset-from>-04:00</utc-offset-from>
    <utc-offset-to>-05:00</utc-offset-to>
   </observance>