Optimize putting data into struct vars

I would do it simpler, by directly allocating values in CCData, and not through a String, which is error prone.

You have no need to create a var secondTry

struct CCdata {
    var id: Int?
    var org_nm: String?
    var org_cd: String?
    var tms: String?
    var tec: String?
    var serno: String?
    var mcn: String?
    var jcn: String?
    var rcvd_dt: Date?
    var cmp_dt: Date?
}

let formatter = DateFormatter()
formatter.dateFormat = "MM/dd/yyyy HH:mm:ss"
let rvcdDate = formatter.date(from: "4/23/2018 0:00:00") ?? Date()          // In case formatter.date returns nil
let cmpDate = formatter.date(from: "5/2/2018 0:00:00") ?? Date()

var firstTry: [CCdata] = [CCdata]()
var firstTrySingle = CCdata(id: 45, org_nm: "HSM73", org_cd: "Q30", tms: "MH-60R", tec: "AHZS", serno: "167043", mcn: "1V4YSQU", jcn: "Q30113239", rcvd_dt: rvcdDate, cmp_dt: cmpDate)

/* REMOVE ALL THIS
var firstTry: [CCdata] = [CCdata]()
var firstTrySingle = CCdata()
print(firstTry.count)
var secondTry = "45    HSM73    Q30    MH-60R    AHZS    167043    1V4YSQU    Q30113239    4/23/2018 0:00:00    5/2/2018 0:00:00"
let secondTry_StrArr = secondTry.components(separatedBy: "    ")
firstTrySingle.id = Int(secondTry_StrArr[0])
firstTrySingle.org_nm = secondTry_StrArr[1]
firstTrySingle.org_cd = secondTry_StrArr[2]
firstTrySingle.tms = secondTry_StrArr[3]
firstTrySingle.tec = secondTry_StrArr[4]
firstTrySingle.serno = secondTry_StrArr[5]
firstTrySingle.mcn = secondTry_StrArr[6]
firstTrySingle.jcn = secondTry_StrArr[7]
let formatter = DateFormatter()
formatter.dateFormat = "MM/dd/yyyy HH:mm:ss"
firstTrySingle.rcvd_dt = formatter.date(from: secondTry_StrArr[8])
firstTrySingle.cmp_dt = formatter.date(from: secondTry_StrArr[9])
*/

firstTry.append(firstTrySingle)
print(firstTry.count)

/* I do not understand what you are doing here, changing the value in the array that you have just defined and never used
     print(firstTry[0].org_nm ?? "Bad Data")
     firstTry[0].org_nm = "HSM72"
     print(firstTry[0].rcvd_dt ?? 2999-09-09)
     print(firstTry[0].cmp_dt ?? 2999-09-09)
     print(firstTry[0].org_nm ?? "Bad Data")
*/
/* THIS can be done simpler
switch firstTry[0].rcvd_dt?.compare(firstTry[0].cmp_dt ?? Date()) {
    case .orderedAscending     :   print("rcvd_dt is earlier than cmp_dt")
    case .orderedDescending    :   print("rcvd_dt is later than cmp_dt")
    case .orderedSame          :   print("The two dates are the same")
    default                    :   print("No answer")
}
print(firstTry[0])
*/

if let rcvd = firstTry[0].rcvd_dt, let cmp = firstTry[0].cmp_dt {
     if rcvd < cmp {
          print("rcvd_dt is earlier than cmp_dt")
     } else if rcvd > cmp {
          print("rcvd_dt is later than cmp_dt")
     } else {
          print("The two dates are the same")
     }
} else {
      print("No answer")
}