>>97
以下のスクリプトを適当な空オブジェクトにアタッチして実行してください(出力されるのはUTC時刻ね)
using UnityEngine;
using System.Collections;
using System.Reflection;
using System;

[assembly: AssemblyVersion("1.0.*")]
public class GetBuildDateTime : MonoBehaviour {
void Start () {
var asm = System.Reflection.Assembly.GetExecutingAssembly ();
var version = asm.GetName ().Version;

int days = version.Build;
int seconds = version.Revision;

DateTime baseDate = new DateTime (2000, 1, 1);
DateTime buildDate = baseDate.AddDays (days);
DateTime buildDateTime = buildDate.AddSeconds (seconds);

Debug.Log ("Build at:" + buildDateTime.ToString ());
}
}