diff --git a/.travis.yml b/.travis.yml
index eac79e047..8e03fba63 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -17,7 +17,7 @@ jobs:
         - ./bin/travis-pre-build.sh
         - export TW5_BUILD_TIDDLYWIKI='./tiddlywiki.js'
         - export TW5_BUILD_VERSION=$(./bin/get-version-number)
-        - export TW5_BUILD_DETAILS="Prerelease built from branch '$TRAVIS_BRANCH' at commit $(git rev-parse HEAD) of $(git remote get-url origin) at $(date '%H:%M:%S +%Y-%m-%d')"
+        - export TW5_BUILD_DETAILS="Prerelease built from branch '$TRAVIS_BRANCH' at commit $(git rev-parse HEAD) of $(git remote get-url origin) at $(date +'%F %T')"
         - export TW5_BUILD_MAIN_EDITION='./editions/prerelease'
         - export TW5_BUILD_OUTPUT='./output/prerelease'
         - ./bin/build-site.sh
@@ -27,7 +27,7 @@ jobs:
         - ./bin/travis-pre-build.sh
         - export TW5_BUILD_TIDDLYWIKI='./node_modules/tiddlywiki/tiddlywiki.js'
         - export TW5_BUILD_VERSION=$(./bin/get-version-number)
-        - export TW5_BUILD_DETAILS="Built from branch '$TRAVIS_BRANCH' at commit $(git rev-parse HEAD) of $(git remote get-url origin) at $(date '%H:%M:%S +%Y-%m-%d')"
+        - export TW5_BUILD_DETAILS="Built from branch '$TRAVIS_BRANCH' at commit $(git rev-parse HEAD) of $(git remote get-url origin) at $(date +'%F %T')"
         - export TW5_BUILD_MAIN_EDITION='./editions/tw5.com'
         - export TW5_BUILD_OUTPUT='./output'
         - ./bin/build-site.sh