Wrap more errors

http/json-date.go

@@ -2,6 +2,7 @@ package http
 
 import (
 	"encoding/json"
+	"fmt"
 	"strings"
 	"time"
 )
@@ -13,14 +14,19 @@ func (j *JSONDate) UnmarshalJSON(b []byte) error {
 	s := strings.Trim(string(b), "\"")
 	t, err := time.Parse("2006-01-02", s)
 	if err != nil {
-		return err
+		return fmt.Errorf("parse date: %w", err)
 	}
 	*j = JSONDate(t)
 	return nil
 }
 
 func (j JSONDate) MarshalJSON() ([]byte, error) {
-	return json.Marshal(time.Time(j))
+	result, err := json.Marshal(time.Time(j))
+	if err != nil {
+		return nil, fmt.Errorf("marshal date: %w", err)
+	}
+
+	return result, nil
 }
 
 // Maybe a Format function for printing your date