diff --git a/binaries/data/mods/public/gamesettings/attributes/StartTime.js b/binaries/data/mods/public/gamesettings/attributes/StartTime.js
new file mode 100644
index 0000000000..24f60a2589
--- /dev/null
+++ b/binaries/data/mods/public/gamesettings/attributes/StartTime.js
@@ -0,0 +1,7 @@
+GameSettings.prototype.Attributes.StartTime = class extends GameSetting
+{
+	onFinalizeAttributes(attribs)
+	{
+		attribs.startTime = Date.now();
+	}
+};
diff --git a/source/ps/Replay.cpp b/source/ps/Replay.cpp
index 8ef85fa93d..b96fffc82a 100644
--- a/source/ps/Replay.cpp
+++ b/source/ps/Replay.cpp
@@ -85,7 +85,14 @@ void CReplayLogger::StartGame(JS::MutableHandleValue attribs)
 	Script::ToJSVal(rq, &mods, g_Mods.GetEnabledModsData());
 	Script::SetProperty(rq, attribs, "mods", mods);
 
-	m_Directory = createDateIndexSubdirectory(VisualReplay::GetDirectoryPath());
+	std::wstring matchID;
+	Script::GetProperty(rq, attribs, "matchID", matchID);
+	ENSURE(!matchID.empty());
+
+	double startTime = 0;
+	Script::GetProperty(rq, attribs, "startTime", startTime);
+
+	m_Directory = createReplaySubdirectory(VisualReplay::GetDirectoryPath(), matchID, startTime);
 	debug_printf("FILES| Replay written to '%s'\n", m_Directory.string8().c_str());
 
 	m_Stream = new std::ofstream(OsString(m_Directory / L"commands.txt"), std::ofstream::out | std::ofstream::trunc);
@@ -95,12 +102,9 @@ void CReplayLogger::StartGame(JS::MutableHandleValue attribs)
 void CReplayLogger::Turn(u32 n, u32 turnLength, std::vector<SimulationCommand>& commands)
 {
 	Script::Request rq(m_ScriptInterface);
-
 	*m_Stream << "turn " << n << " " << turnLength << "\n";
-
 	for (SimulationCommand& command : commands)
 		*m_Stream << "cmd " << command.player << " " << Script::StringifyJSON(rq, &command.data, false) << "\n";
-
 	*m_Stream << "end\n";
 	m_Stream->flush();
 }
diff --git a/source/ps/Util.cpp b/source/ps/Util.cpp
index 1ac56c268b..b2741fe2fe 100644
--- a/source/ps/Util.cpp
+++ b/source/ps/Util.cpp
@@ -33,8 +33,10 @@
 #include "ps/Filesystem.h"
 #include "ps/Pyrogenesis.h"
 
+#include <chrono>
 #include <ctime>
 #include <filesystem>
+#include <fmt/format.h>
 #include <iomanip>
 #include <memory>
 #include <sstream>
@@ -119,6 +121,26 @@ OsPath createDateIndexSubdirectory(const OsPath& parentDir)
 	return path;
 }
 
+OsPath createReplaySubdirectory(const OsPath& parentDir, const std::wstring& matchID, double startTimeMillis)
+{
+	using namespace std::chrono;
+
+	const system_clock::time_point timePoint{milliseconds(static_cast<i64>(startTimeMillis))};
+	const year_month_day ymd{floor<days>(timePoint)};
+	const std::string baseName = fmt::format("{:04}-{:02}-{:02}_{}",
+		static_cast<int>(ymd.year()), static_cast<unsigned>(ymd.month()), static_cast<unsigned>(ymd.day()),
+		utf8_from_wstring(matchID));
+
+	for (int i = 0; ; ++i)
+	{
+		const OsPath path = parentDir / (i == 0 ? baseName : fmt::format("{}_{:04}", baseName, i));
+		if (DirectoryExists(path) || std::filesystem::is_regular_file(path.string()))
+			continue;
+		ENSURE(CreateDirectories(path, 0700) == INFO::OK);
+		return path;
+	}
+}
+
 std::string Hexify(const std::string& s)
 {
 	std::stringstream str;
diff --git a/source/ps/Util.h b/source/ps/Util.h
index 36cd505f4e..a660c4d128 100644
--- a/source/ps/Util.h
+++ b/source/ps/Util.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2025 Wildfire Games.
+/* Copyright (C) 2026 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -35,6 +35,8 @@ CStr GetStatusAsString(Status status);
 
 OsPath createDateIndexSubdirectory(const OsPath& parentDir);
 
+OsPath createReplaySubdirectory(const OsPath& parentDir, const std::wstring& matchID, double startTimeMillis);
+
 Status tex_write(Tex* t, const VfsPath& filename);
 
 std::string Hexify(const std::string& s);