FlickrNet.Utils.DateToUnixTimestamp C# (CSharp) Method

        internal static long DateToUnixTimestamp(DateTime date)
        {
            TimeSpan ts = date - unixStartDate;
            return (long)ts.TotalSeconds;
        }

 internal static void PartialOptionsIntoArray(PartialSearchOptions options, Hashtable parameters)
 {
     if (options.MinUploadDate != DateTime.MinValue)
     {
         parameters.Add("min_uploaded_date", Utils.DateToUnixTimestamp(options.MinUploadDate).ToString());
     }
     if (options.MaxUploadDate != DateTime.MinValue)
     {
         parameters.Add("max_uploaded_date", Utils.DateToUnixTimestamp(options.MaxUploadDate).ToString());
     }
     if (options.MinTakenDate != DateTime.MinValue)
     {
         parameters.Add("min_taken_date", options.MinTakenDate.ToString("yyyy-MM-dd HH:mm:ss"));
     }
     if (options.MaxTakenDate != DateTime.MinValue)
     {
         parameters.Add("max_taken_date", options.MaxTakenDate.ToString("yyyy-MM-dd HH:mm:ss"));
     }
     if (options.Extras != PhotoSearchExtras.None)
     {
         parameters.Add("extras", options.ExtrasString);
     }
     if (options.SortOrder != PhotoSearchSortOrder.None)
     {
         parameters.Add("sort", options.SortOrderString);
     }
     if (options.PerPage > 0)
     {
         parameters.Add("per_page", options.PerPage.ToString());
     }
     if (options.Page > 0)
     {
         parameters.Add("page", options.Page.ToString());
     }
     if (options.PrivacyFilter != PrivacyFilter.None)
     {
         parameters.Add("privacy_filter", options.PrivacyFilter.ToString("d"));
     }
 }