diff --git a/pica-wekan-scripts/policy.sh b/pica-wekan-scripts/policy.sh
index df41ab6c3c94832f6250f29ee0e463e249dade66..f2f28f37ae68ab644e649a8b0ae91243b0058236 100755
--- a/pica-wekan-scripts/policy.sh
+++ b/pica-wekan-scripts/policy.sh
@@ -9,7 +9,8 @@ boardExpirationDurationMonths=${boardExpirationDurationMonths-12} # mois
 boardExpirationDurationDays=${boardExpirationDurationDays-0} # jours
 url=${url-"https://wekan.test.picasoft.net"}
 # Deadline = somme des durées du dessus
-deadlineTimeStamp=$(date -d "-"$boardExpirationDurationYears"years-"$boardExpirationDurationMonths"months-"$boardExpirationDurationDays"days" +%s)
+deadlineTimeStamp=$(date --date $boardExpirationDurationYears" years ago "$boardExpirationDurationMonths" months ago "$boardExpirationDurationDays" days ago" +%s)
+
 delete=false
 while getopts "d" option
 do