diff --git a/action.yml b/action.yml
index 7af8026..1258333 100644
--- a/action.yml
+++ b/action.yml
@@ -9,7 +9,7 @@ outputs:
   new_version:
     description: The bumped calver version.
 runs:
-  using: node12
+  using: node16
   main: dist/index.js
 branding:
   icon: bookmark
diff --git a/dist/index.js b/dist/index.js
index f01ddf0..f1a33f1 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -1565,12 +1565,7 @@ class Calver {
         this.year = year;
         this.month = month;
         this.index = Number(index);
-        if (currentVersion.startsWith('v')) {
-            this.hasVPrefix = true;
-        }
-        else {
-            this.hasVPrefix = false;
-        }
+        this.hasVPrefix = currentVersion.startsWith('v') ? true : false;
     }
     toString() {
         let output = `${this.year}.${this.month}.${this.index}`;
@@ -1586,8 +1581,8 @@ class Calver {
             this.index += 1;
         }
         else {
-            this.year = String('00' + now.getFullYear()).slice(-2);
-            this.month = String('00' + now.getMonth() + 1).slice(-2);
+            this.year = String(now.getFullYear()).slice(-2);
+            this.month = String('0' + (Number(now.getMonth()) + 1)).slice(-2);
             this.index = 0;
         }
         return this;
diff --git a/src/calver.ts b/src/calver.ts
index d191b45..bf2c85b 100644
--- a/src/calver.ts
+++ b/src/calver.ts
@@ -19,11 +19,7 @@ export class Calver {
     this.year = year;
     this.month = month;
     this.index = Number(index);
-    if (currentVersion.startsWith('v')) {
-      this.hasVPrefix = true;
-    } else {
-      this.hasVPrefix = false;
-    }
+    this.hasVPrefix = currentVersion.startsWith('v') ? true : false;
   }
 
   toString(): string {
@@ -42,8 +38,8 @@ export class Calver {
     ) {
       this.index += 1;
     } else {
-      this.year = String('00' + now.getFullYear()).slice(-2);
-      this.month = String('00' + (now.getMonth() + 1)).slice(-2);
+      this.year = String(now.getFullYear()).slice(-2);
+      this.month = String('0' + (Number(now.getMonth()) + 1)).slice(-2);
       this.index = 0;
     }
     return this;