diff --git a/.gitea/workflows/develop.yml b/.gitea/workflows/develop.yml
index 0e7d5d2..57b331a 100644
--- a/.gitea/workflows/develop.yml
+++ b/.gitea/workflows/develop.yml
@@ -27,7 +27,7 @@ jobs:
                   # PR head commit instead so tags map to actual git history.
                   FULL_SHA="${{ gitea.event.pull_request.head.sha || gitea.sha }}"
                   SHORT_SHA="${FULL_SHA:0:7}"
-                  BUILD_TIME=$(date -u +%Y%m%d-%H%M%S)
+                  BUILD_TIME=$(date -u +%Y-%m-%d_%H-%M-%S)
                   echo "sha=${SHORT_SHA}" >> "$GITHUB_OUTPUT"
                   echo "tag=${BUILD_TIME}-${SHORT_SHA}" >> "$GITHUB_OUTPUT"