diff --git a/pkg/tplfunc/date.go b/pkg/tplfunc/date.go
index f65c025..e2f6e81 100644
--- a/pkg/tplfunc/date.go
+++ b/pkg/tplfunc/date.go
@@ -3,6 +3,8 @@ package tplfunc
 import (
 	"text/template"
 	"time"
+
+	"github.com/spf13/cast"
 )
 
 var Date = []Func{Now(), FormatDate()}
@@ -22,9 +24,9 @@ func FormatDate() Func {
 			case 0:
 				panic("formatDate() requires at least 1 argument")
 			case 1:
-				return time.Unix(int64(args[0].(int)), 0).Format("20060102150405")
+				return time.Unix(cast.ToInt64(args[0]), 0).Format("20060102150405")
 			case 2:
-				return time.Unix(int64(args[0].(int)), 0).Format(args[1].(string))
+				return time.Unix(cast.ToInt64(args[0]), 0).Format(args[1].(string))
 			default:
 				panic("formatDate() requires at most 2 arguments")
 			}