update util

Helpers/SimApiUtil.cs

@@ -10,11 +10,22 @@ namespace SimApi.Helpers
 {
     public static class SimApiUtil
     {
+        /// <summary>
+        /// 当前CST时间
+        /// </summary>
         public static DateTime CstNow
         {
             get => DateTime.UtcNow.AddHours(8);
         }
 
+        /// <summary>
+        /// 当前秒级时间戳
+        /// </summary>
+        public static double TimestampNow
+        {
+            get => (DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, 0)).TotalSeconds;
+        }
+
         /// <summary>
         /// 检测手机号是否正确
         /// </summary>
@@ -58,14 +69,5 @@ namespace SimApi.Helpers
                 Encoder = JavaScriptEncoder.Create(UnicodeRanges.All)
             });
         }
-
-        /// <summary>
-        /// 获取 CST 当前时间
-        /// </summary>
-        /// <returns></returns>
-        public static DateTime GetCstNow()
-        {
-            return CstNow;
-        }
     }
 }