From ed7f2588e409b6d154f4a08bd0029ef1e7beb06b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Carl=20=C3=85stholm?= <carl@astholm.se>
Date: Wed, 5 Nov 2025 00:50:19 +0100
Subject: [PATCH] io: Translate Windows `Clock.real` timestamps to the
 POSIX/Unix epoch

This fixes `std.http.Client` TLS certificate validation on Windows.
---
 lib/std/Io/Threaded.zig | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/lib/std/Io/Threaded.zig b/lib/std/Io/Threaded.zig
index 11f9b149ca..58febae64a 100644
--- a/lib/std/Io/Threaded.zig
+++ b/lib/std/Io/Threaded.zig
@@ -2864,7 +2864,8 @@ fn nowWindows(userdata: ?*anyopaque, clock: Io.Clock) Io.Clock.Error!Io.Timestam
         .real => {
             // RtlGetSystemTimePrecise() has a granularity of 100 nanoseconds
             // and uses the NTFS/Windows epoch, which is 1601-01-01.
-            return .{ .nanoseconds = @as(i96, windows.ntdll.RtlGetSystemTimePrecise()) * 100 };
+            const epoch_ns = std.time.epoch.windows * std.time.ns_per_s;
+            return .{ .nanoseconds = @as(i96, windows.ntdll.RtlGetSystemTimePrecise()) * 100 + epoch_ns };
         },
         .awake, .boot => {
             // QPC on windows doesn't fail on >= XP/2000 and includes time suspended.