private void SaveAssignmentData()
        {
            _currentPeriod.assignments.Clear();
            foreach (DataGridViewRow row in MatchRegime.Rows)
            {
                if (row.IsNewRow)
                {
                    continue;
                }

                var newAss = new Assignment();
                newAss.home = new Team {
                    teamName = row.Cells["hometeam"].Value.ToString()
                };
                newAss.guest = new Team {
                    teamName = row.Cells["guestteam"].Value.ToString()
                };
                newAss.field = new Field {
                    fieldName = row.Cells["field"].Value.ToString()
                };
                newAss.time    = row.Cells["time"].Value?.ToString() ?? "";
                newAss.referee = new Core.Referee {
                    name = row.Cells["referee"].Value?.ToString() ?? ""
                };
                newAss.helperA = new Core.Referee {
                    name = row.Cells["refereeHelperA"].Value?.ToString() ?? ""
                };
                newAss.helperB = new Core.Referee {
                    name = row.Cells["refereeHelperB"].Value?.ToString() ?? ""
                };
                newAss.watchRef = new WatchRef {
                    name = row.Cells["refereeObserver"].Value?.ToString() ?? ""
                };
                _currentPeriod.assignments.Add(newAss);
            }

            // For each saved period
            foreach (var p in ApplicationData.Periods)
            {
                // If our period exists in the data
                if (p.Equals(_currentPeriod))
                {
                    // update p's asssignments.
                    p.assignments = _currentPeriod.assignments;
                    ReloadAssignmentDataIntoGrid();
                    return;
                }
            }

            // Else just create it and add it to the data.
            ApplicationData.AddPeriod(_currentPeriod);
            ReloadAssignmentDataIntoGrid();
        }