diff --git a/.github/workflows/release_android.yml b/.github/workflows/release_android.yml
index 8bfc0f3d..9c54d472 100644
--- a/.github/workflows/release_android.yml
+++ b/.github/workflows/release_android.yml
@@ -17,17 +17,25 @@ jobs:
         shell: bash
         run: |
           TAG="${{ github.event.release.tag_name }}"
-          VERSION="${TAG#v}"
-          IFS='.' read -r MAJOR MINOR PATCH <<< "$VERSION"
-          MAJOR=${MAJOR:-0}
-          MINOR=${MINOR:-0}
-          PATCH=${PATCH:-0}
+          if [[ ! "$TAG" =~ ^v([0-9]{4})\.([0-9]{1,2})\.([0-9]{1,2})$ ]]; then
+            echo "Tag '$TAG' does not match expected format vYYYY.M.D" >&2
+            exit 1
+          fi
+          YEAR="${BASH_REMATCH[1]}"
+          MONTH="${BASH_REMATCH[2]}"
+          DAY="${BASH_REMATCH[3]}"
 
-          # Android versionCode must be a positive integer
-          VERSION_CODE=$(( MAJOR * 1000000 + MINOR * 1000 + PATCH ))
+          # SemVer display version: YY.M.DOY  (Resizetizer-safe 3-part version)
+          YY=$(( YEAR - 2000 ))
+          DOY=$(date -d "$YEAR-$MONTH-$DAY" +%j | sed 's/^0*//')
 
-          echo "APP_VERSION=$VERSION" >> $GITHUB_ENV
-          echo "APP_ANDROID_VERSION=$VERSION_CODE" >> $GITHUB_ENV
+          APP_DISPLAY_VERSION="$YY.$MONTH.$DOY"
+
+          # Android versionCode: monotonic integer  YYYY*1000 + DOY
+          APP_ANDROID_VERSION=$(( YEAR * 1000 + DOY ))
+
+          echo "APP_DISPLAY_VERSION=$APP_DISPLAY_VERSION" >> $GITHUB_ENV
+          echo "APP_ANDROID_VERSION=$APP_ANDROID_VERSION" >> $GITHUB_ENV
 
       - name: Install KVM and Android SDK (x86)
         run: |
@@ -71,7 +79,7 @@ jobs:
             -f net10.0-android \
             -c Release \
             --no-restore \
-            /p:ApplicationDisplayVersion=${{ env.APP_VERSION }} \
+            /p:ApplicationDisplayVersion=${{ env.APP_DISPLAY_VERSION }} \
             /p:ApplicationVersion=${{ env.APP_ANDROID_VERSION }} \
             /p:AndroidSigningKeyStore=$(pwd)/android_keystore.jks \
             /p:AndroidSigningKeyAlias=${{ secrets.ANDROID_KEY_ALIAS }} \
diff --git a/.github/workflows/release_windows.yml b/.github/workflows/release_windows.yml
index ed014e1f..cccc236c 100644
--- a/.github/workflows/release_windows.yml
+++ b/.github/workflows/release_windows.yml
@@ -17,18 +17,25 @@ jobs:
         shell: powershell
         run: |
           $tag = "${{ github.event.release.tag_name }}"
-          $version = $tag.TrimStart('v')
-          $parts = $version.Split('.')
+          if ($tag -notmatch '^v(\d{4})\.(\d{1,2})\.(\d{1,2})$') {
+            Write-Error "Tag '$tag' does not match expected format vYYYY.M.D"
+            exit 1
+          }
+          $year  = [int]$Matches[1]
+          $month = [int]$Matches[2]
+          $day   = [int]$Matches[3]
 
-          $major = [int]($parts[0])
-          $minor = if ($parts.Length -gt 1) { [int]($parts[1]) } else { 0 }
-          $patch = if ($parts.Length -gt 2) { [int]($parts[2]) } else { 0 }
+          # SemVer display version: YY.M.DOY  (Resizetizer-safe 3-part version)
+          $yy  = $year - 2000
+          $date = Get-Date -Year $year -Month $month -Day $day
+          $doy  = $date.DayOfYear
+          $displayVersion = "$yy.$month.$doy"
 
-          # Valid MSIX/Appx version: A.B.C.D where each part is 0..65535
-          $msixVersion = "$major.$minor.$patch.0"
+          # Valid MSIX/Appx version: YYYY.M.D.0  (each part 0..65535)
+          $msixVersion = "$year.$month.$day.0"
 
-          echo "APP_VERSION=$version" >> $env:GITHUB_ENV
-          echo "APP_MSIX_VERSION=$msixVersion" >> $env:GITHUB_ENV
+          echo "APP_DISPLAY_VERSION=$displayVersion" >> $env:GITHUB_ENV
+          echo "APP_MSIX_VERSION=$msixVersion"       >> $env:GITHUB_ENV
 
       - name: Setup MSBuild
         uses: microsoft/setup-msbuild@v1.1
@@ -66,7 +73,7 @@ jobs:
           dotnet publish TransactionProcessor.Mobile/TransactionProcessor.Mobile.csproj `
             -c Release `
             -f net10.0-windows10.0.19041.0 `
-            /p:ApplicationDisplayVersion=${{ env.APP_VERSION }} `
+            /p:ApplicationDisplayVersion=${{ env.APP_DISPLAY_VERSION }} `
             /p:ApplicationVersion=${{ env.APP_MSIX_VERSION }} `
             /p:AppxPackageSigningEnabled=true `
             /p:PackageCertificateThumbprint="${{ secrets.WINDOWSSIGNINGCERTTHUMBPRINT }}"
diff --git a/README.md b/README.md
index 2e648086..6b995c30 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,33 @@
 # TransactionMobile
 
 ![Alt](https://repobeats.axiom.co/api/embed/8c4c40e2db665c43af4c4e1014a3dca92fe330aa.svg "Repobeats analytics image")
+
+## Release versioning
+
+Releases are tagged in calendar format: **`vYYYY.M.D`** (e.g. `v2026.4.1`).
+
+The release workflows derive three version values from this tag automatically.
+
+| Value | Formula | Example (`v2026.4.1`, DOY = 91) |
+|---|---|---|
+| **ApplicationDisplayVersion** (SemVer 3-part) | `YY.M.DOY` | `26.4.91` |
+| **Windows MSIX/Appx package version** | `YYYY.M.D.0` | `2026.4.1.0` |
+| **Android versionCode** | `YYYY * 1000 + DOY` | `2026091` |
+
+Where:
+- `YY = YYYY - 2000`
+- `M = month number` (1–12)
+- `D = day of month` (1–31)
+- `DOY = day-of-year` (1–366)
+
+### Key properties
+
+- **ApplicationDisplayVersion** is a valid 3-part SemVer-like version, satisfying `Microsoft.Maui.Resizetizer` validation requirements.
+- **Windows package version** uses the full 4-part `YYYY.M.D.0` format required by MSIX/Appx.
+- **Android versionCode** is a monotonically increasing integer across all releases.
+
+### Creating a release
+
+Tag format: `vYYYY.M.D` (single or double digit month/day both accepted).
+
+Example tags: `v2026.4.1`, `v2026.12.31`, `v2027.1.5`