diff --git a/php/classes/TimeTableMgr.php b/php/classes/TimeTableMgr.php
index 181cc7b..4244f65 100644
--- a/php/classes/TimeTableMgr.php
+++ b/php/classes/TimeTableMgr.php
@@ -342,8 +342,10 @@ class TimeTableMgr extends AmdaObjectMgr
 				$doyRegex = '(\d{4}) (\d{2,3}) (\d{2}) (\d{2}) (\d{2})( \d{2})?';
 
 				if (preg_match('/^' . $doyRegex . ' ' . $doyRegex . '$/', $line)) {
-					$startDate = DateTime::createFromFormat($doyFormat, substr($line, 0, 17))->format($isoFormat);
-					$stopDate = DateTime::createFromFormat($doyFormat, substr($line, 18))->format($isoFormat);
+					$start = DateTime::createFromFormat($doyFormat, substr($line, 0, 17));
+					$stop = DateTime::createFromFormat($doyFormat, substr($line, 18));
+					$startDate = $start->sub(new DateInterval('P1D'))->format($isoFormat);
+					$stopDate = $stop->sub(new DateInterval('P1D'))->format($isoFormat);
 				} else {
 					$dateLength = round((strlen($line)-1) / 2);
 
--
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