using System;

using Cronos;

using Newtonsoft.Json;

using System.Text;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

                string jsonString= "";///Put Json string you want to test

                string exp="";//Put Coron exp you want to test

                var jsonobject = Newtonsoft.Json.JsonConvert.DeserializeObject<dynamic>(jsonString);

                CronExpression expression = CronExpression.Parse(exp);

                DateTime? next = expression.GetNextOccurrence(Convert.ToDateTime("2020 - 06 - 01 13:46:47.357").ToUniversalTime(), TimeZoneInfo.Local);

                var dateoffset = Convert.ToDateTime("2020 - 06 - 01 13:46:47.357").ToUniversalTime().Subtract(next.GetValueOrDefault());

                StringBuilder sb = new StringBuilder();

                var kvlst = new List<KeyValuePair<string, string>>();

                foreach (var item in jsonobject)

                {

                    string str = JsonConvert.SerializeObject(item);

                    var dicobj = JsonConvert.DeserializeObject<Dictionary<string, string>>(str);

                    foreach (var dicitem in dicobj)

                    {

                        var kv = new KeyValuePair<string, string>();

                        DateTime newdate = DateTime.MinValue;

                        if (DateTime.TryParse(dicitem.Value, out DateTime datetimeItemValue))

                        {

                            DateTime jobrundate = Convert.ToDateTime("2020 - 06 - 01 13:46:47.357");

                            newdate = datetimeItemValue.Subtract(dateoffset);

                           kv = new KeyValuePair<string, string>(dicitem.Key, newdate.ToString());

                        }

                        if (newdate != DateTime.MinValue)

                        {

                            kv = new KeyValuePair<string, string>(dicitem.Key, newdate.ToString());

                        }

                        else

                        {

                            kv = new KeyValuePair<string, string>(dicitem.Key, dicitem.Value);

                        }

                        kvlst.Add(kv);

​

​

                    }

​

                    string disctojason = JsonConvert.SerializeObject(kvlst);

                    sb.Append(disctojason);

                }

                var test = JsonConvert.SerializeObject(sb.ToString());

        Console.WriteLine(test);

    }

}