Add better date string formatting

osu.Game.Tournament/Components/DateTextBox.cs

@@ -0,0 +1,44 @@
+// Copyright (c) 2007-2018 ppy Pty Ltd <contact@ppy.sh>.
+// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
+
+using System;
+using osu.Framework.Configuration;
+using osu.Game.Graphics.UserInterface;
+using osu.Game.Overlays.Settings;
+
+namespace osu.Game.Tournament.Components
+{
+    public class DateTextBox : SettingsTextBox
+    {
+        public new Bindable<DateTimeOffset> Bindable
+        {
+            get { return bindable; }
+
+            set
+            {
+                bindable = value;
+                bindable.BindValueChanged(dto =>
+                    base.Bindable.Value = dto.ToUniversalTime().ToString("yyyy-MM-ddTHH:mm:ssZ"), true);
+            }
+        }
+
+        // hold a reference to the provided bindable so we don't have to in every settings section.
+        private Bindable<DateTimeOffset> bindable;
+
+        public DateTextBox()
+        {
+            base.Bindable = new Bindable<string>();
+            ((OsuTextBox)Control).OnCommit = (sender, newText) =>
+            {
+                try
+                {
+                    bindable.Value = DateTimeOffset.Parse(sender.Text);
+                }
+                catch
+                {
+                    bindable.TriggerChange();
+                }
+            };
+        }
+    }
+}