1 files changed, 68 insertions, 0 deletions
diff --git a/Ryujinx.HLE/HOS/Services/Time/TimeZone/TimeZoneContentManager.cs b/Ryujinx.HLE/HOS/Services/Time/TimeZone/TimeZoneContentManager.cs
index 70e1dcb4..e2576425 100644
--- a/Ryujinx.HLE/HOS/Services/Time/TimeZone/TimeZoneContentManager.cs
+++ b/Ryujinx.HLE/HOS/Services/Time/TimeZone/TimeZoneContentManager.cs
@@ -10,6 +10,7 @@ using Ryujinx.HLE.FileSystem;
 using Ryujinx.HLE.FileSystem.Content;
 using Ryujinx.HLE.HOS.Services.Time.Clock;
 using Ryujinx.HLE.Utilities;
+using System;
 using System.Collections.Generic;
 using System.IO;
 
@@ -117,6 +118,73 @@ namespace Ryujinx.HLE.HOS.Services.Time.TimeZone
             }
         }
 
+        public IEnumerable<(int Offset, string Location, string Abbr)> ParseTzOffsets()
+        {
+            var tzBinaryContentPath = GetTimeZoneBinaryTitleContentPath();
+
+            if (string.IsNullOrEmpty(tzBinaryContentPath))
+            {
+                return new[] { (0, "UTC", "UTC") };
+            }
+
+            List<(int Offset, string Location, string Abbr)> outList = new List<(int Offset, string Location, string Abbr)>();
+            var now = System.DateTimeOffset.Now.ToUnixTimeSeconds();
+            using (IStorage ncaStorage = new LocalStorage(_virtualFileSystem.SwitchPathToSystemPath(tzBinaryContentPath), FileAccess.Read, FileMode.Open))
+            using (IFileSystem romfs = new Nca(_virtualFileSystem.KeySet, ncaStorage).OpenFileSystem(NcaSectionType.Data, _fsIntegrityCheckLevel))
+            {
+                foreach (string locName in LocationNameCache)
+                {
+                    if (locName.StartsWith("Etc"))
+                    {
+                        continue;
+                    }
+
+                    if (romfs.OpenFile(out IFile tzif, $"/zoneinfo/{locName}".ToU8Span(), OpenMode.Read).IsFailure())
+                    {
+                        Logger.PrintError(LogClass.ServiceTime, $"Error opening /zoneinfo/{locName}");
+                        continue;
+                    }
+
+                    using (tzif)
+                    {
+                        TimeZone.ParseTimeZoneBinary(out TimeZoneRule tzRule, tzif.AsStream());
+
+                        TimeTypeInfo ttInfo;
+                        if (tzRule.TimeCount > 0) // Find the current transition period
+                        {
+                            int fin = 0;
+                            for (int i = 0; i < tzRule.TimeCount; ++i)
+                            {
+                                if (tzRule.Ats[i] <= now)
+                                {
+                                    fin = i;
+                                }
+                            }
+                            ttInfo = tzRule.Ttis[tzRule.Types[fin]];
+                        }
+                        else if (tzRule.TypeCount >= 1) // Otherwise, use the first offset in TTInfo
+                        {
+                            ttInfo = tzRule.Ttis[0];
+                        }
+                        else
+                        {
+                            Logger.PrintError(LogClass.ServiceTime, $"Couldn't find UTC offset for zone {locName}");
+                            continue;
+                        }
+
+                        var abbrStart = tzRule.Chars.AsSpan(ttInfo.AbbreviationListIndex);
+                        int abbrEnd = abbrStart.IndexOf('\0');
+
+                        outList.Add((ttInfo.GmtOffset, locName, abbrStart.Slice(0, abbrEnd).ToString()));
+                    }
+                }
+            }
+
+            outList.Sort();
+
+            return outList;
+        }
+
         private bool IsLocationNameValid(string locationName)
         {
             foreach (string cachedLocationName in LocationNameCache)