diff --git a/util.go b/util.go
index 0d3a181..cb7f0ee 100644
--- a/util.go
+++ b/util.go
@@ -4,6 +4,7 @@ import (
 	"reflect"
 	"strconv"
 	"strings"
+	"time"
 )
 
 // extractTypeInternal gets the actual underlying type of field value.
@@ -229,6 +230,15 @@ func asInt(param string) int64 {
 	return i
 }
 
+// asIntFromTimeDuration parses param as time.Duration and returns it as int64
+// or panics on error.
+func asIntFromTimeDuration(param string) int64 {
+	d, err := time.ParseDuration(param)
+	panicIf(err)
+
+	return int64(d)
+}
+
 // asUint returns the parameter as a uint64
 // or panics if it can't convert
 func asUint(param string) uint64 {