diff --git a/lib/std/Io/Threaded.zig b/lib/std/Io/Threaded.zig
index 7e52f136567f575610e5262022fc3996893c38fa..3899af5adc487cbf5a22b551eb8baf03bce472b3 100644
--- a/lib/std/Io/Threaded.zig
+++ b/lib/std/Io/Threaded.zig
@@ -14242,8 +14242,8 @@ fn timestampToPosix(nanoseconds: i96) posix.timespec {
 
 pub fn setTimestampToPosix(set_ts: File.SetTimestamp) posix.timespec {
     return switch (set_ts) {
-        .unchanged => .OMIT,
-        .now => .NOW,
+        .unchanged => posix.UTIME.OMIT,
+        .now => posix.UTIME.NOW,
         .new => |t| timestampToPosix(t.nanoseconds),
     };
 }
diff --git a/lib/std/c.zig b/lib/std/c.zig
index 3e1a2d28ca6473a6f77c707ac987808541046fa5..73c9ef0b13d72d95b531a25c3c9601ee81f34743 100644
--- a/lib/std/c.zig
+++ b/lib/std/c.zig
@@ -94,13 +94,36 @@ pub const off_t = switch (native_os) {
     else => i64,
 };
 
+/// For use with `utimensat` and `futimens`.
+pub const UTIME = switch (native_os) {
+    .dragonfly, .freebsd, .illumos, .driverkit, .ios, .maccatalyst, .macos, .tvos, .visionos, .watchos, .wasi => struct {
+        pub const NOW: timespec = .{ .sec = 0, .nsec = -1 };
+        pub const OMIT: timespec = .{ .sec = 0, .nsec = -2 };
+    },
+    .emscripten => emscripten.UTIME,
+    .haiku => struct {
+        pub const NOW: timespec = .{ .sec = 0, .nsec = 1000000000 };
+        pub const OMIT: timespec = .{ .sec = 0, .nsec = 1000000001 };
+    },
+    .linux => linux.UTIME,
+    .netbsd => struct {
+        pub const NOW: timespec = .{ .sec = 0, .nsec = 0x3fffffff };
+        pub const OMIT: timespec = .{ .sec = 0, .nsec = 0x3ffffffe };
+    },
+    .openbsd, .serenity => struct {
+        pub const NOW: timespec = .{ .sec = 0, .nsec = -2 };
+        pub const OMIT: timespec = .{ .sec = 0, .nsec = -1 };
+    },
+    else => void,
+};
+
 pub const timespec = switch (native_os) {
     .linux => linux.timespec,
     .emscripten => emscripten.timespec,
     // lib/libc/include/wasm-wasi-musl/__struct_timespec.h
     .wasi => extern struct {
         sec: time_t,
-        nsec: isize,
+        nsec: c_long,
 
         pub fn fromTimestamp(tm: wasi.timestamp_t) timespec {
             const sec: wasi.timestamp_t = tm / 1_000_000_000;
@@ -115,74 +138,12 @@ pub const timespec = switch (native_os) {
             return @as(wasi.timestamp_t, @intCast(ts.sec * 1_000_000_000)) +
                 @as(wasi.timestamp_t, @intCast(ts.nsec));
         }
-
-        // lib/libc/include/wasm-wasi-musl/__header_sys_stat.h
-
-        /// For use with `utimensat` and `futimens`.
-        pub const NOW: timespec = .{
-            .sec = 0,
-            .nsec = -1,
-        };
-
-        /// For use with `utimensat` and `futimens`.
-        pub const OMIT: timespec = .{
-            .sec = 0,
-            .nsec = -2,
-        };
     },
     // https://github.com/SerenityOS/serenity/blob/0a78056453578c18e0a04a0b45ebfb1c96d59005/Kernel/API/POSIX/time.h#L17-L20
-    .windows, .serenity => extern struct {
+    .dragonfly, .freebsd, .netbsd, .openbsd, .illumos, .haiku, .serenity, .driverkit, .ios, .maccatalyst, .macos, .tvos, .visionos, .watchos, .windows => extern struct {
         sec: time_t,
         nsec: c_long,
     },
-    .dragonfly, .freebsd, .driverkit, .ios, .maccatalyst, .macos, .tvos, .visionos, .watchos => extern struct {
-        sec: isize,
-        nsec: isize,
-
-        /// For use with `utimensat` and `futimens`.
-        pub const NOW: timespec = .{
-            .sec = 0,
-            .nsec = -1,
-        };
-
-        /// For use with `utimensat` and `futimens`.
-        pub const OMIT: timespec = .{
-            .sec = 0,
-            .nsec = -2,
-        };
-    },
-    .netbsd, .illumos => extern struct {
-        sec: i64,
-        nsec: isize,
-
-        /// For use with `utimensat` and `futimens`.
-        pub const NOW: timespec = .{
-            .sec = 0,
-            .nsec = 0x3fffffff,
-        };
-
-        /// For use with `utimensat` and `futimens`.
-        pub const OMIT: timespec = .{
-            .sec = 0,
-            .nsec = 0x3ffffffe,
-        };
-    },
-    .openbsd, .haiku => extern struct {
-        sec: time_t,
-        nsec: isize,
-
-        /// For use with `utimensat` and `futimens`.
-        pub const NOW: timespec = .{
-            .sec = 0, // ignored
-            .nsec = -2,
-        };
-
-        /// For use with `utimensat` and `futimens`.
-        pub const OMIT: timespec = .{
-            .sec = 0, // ignored
-            .nsec = -1,
-        };
-    },
     else => void,
 };
 
@@ -4128,7 +4089,7 @@ pub const in6_pktinfo = switch (native_os) {
 };
 pub const itimerspec = switch (native_os) {
     .linux => linux.itimerspec,
-    .haiku => extern struct {
+    .dragonfly, .freebsd, .netbsd, .openbsd, .haiku, .illumos, .windows, .wasi => extern struct {
         interval: timespec,
         value: timespec,
     },
@@ -7037,18 +6998,19 @@ pub const stack_t = switch (native_os) {
 };
 pub const time_t = switch (native_os) {
     .linux => linux.time_t,
+    .dragonfly, .illumos, .driverkit, .ios, .maccatalyst, .macos, .tvos, .visionos, .watchos => c_long,
     .emscripten => emscripten.time_t,
-    .haiku, .dragonfly => isize,
-    // lib/libc/include/wasm-wasi-musl/__typedef_time_t.h
+    .freebsd, .haiku => if (native_arch == .x86) c_int else c_longlong,
     // https://github.com/SerenityOS/serenity/blob/b98f537f117b341788023ab82e0c11ca9ae29a57/Kernel/API/POSIX/sys/types.h#L47
-    else => i64,
+    // lib/libc/include/wasm-wasi-musl/__typedef_time_t.h
+    .netbsd, .openbsd, .serenity, .wasi => c_longlong,
+    else => void,
 };
 pub const suseconds_t = switch (native_os) {
+    .dragonfly, .freebsd, .openbsd, .illumos => c_long,
+    .netbsd, .haiku, .driverkit, .ios, .maccatalyst, .macos, .tvos, .visionos, .watchos => c_int,
     // https://github.com/SerenityOS/serenity/blob/b98f537f117b341788023ab82e0c11ca9ae29a57/Kernel/API/POSIX/sys/types.h#L49
-    .illumos, .serenity => i64,
-    .freebsd, .dragonfly => c_long,
-    .netbsd => c_int,
-    .haiku => i32,
+    .serenity, .wasi => c_longlong,
     else => void,
 };
 
@@ -7059,32 +7021,20 @@ pub const timeval = switch (native_os) {
         sec: c_long,
         usec: c_long,
     },
-    .driverkit, .ios, .maccatalyst, .macos, .tvos, .visionos, .watchos => extern struct {
-        sec: c_long,
-        usec: i32,
-    },
     // https://github.com/SerenityOS/serenity/blob/6b6eca0631c893c5f8cfb8274cdfe18e2d0637c0/Kernel/API/POSIX/sys/time.h#L15-L18
-    .dragonfly, .netbsd, .freebsd, .illumos, .serenity => extern struct {
+    .dragonfly, .freebsd, .netbsd, .openbsd, .haiku, .illumos, .serenity, .driverkit, .ios, .maccatalyst, .macos, .tvos, .visionos, .watchos, .wasi => extern struct {
         /// seconds
         sec: time_t,
         /// microseconds
         usec: suseconds_t,
     },
-    .openbsd => extern struct {
-        sec: time_t,
-        usec: c_long,
-    },
     else => void,
 };
 pub const timezone = switch (native_os) {
     .linux => linux.timezone,
     .emscripten => emscripten.timezone,
-    .openbsd, .driverkit, .ios, .maccatalyst, .macos, .tvos, .visionos, .watchos => extern struct {
-        minuteswest: i32,
-        dsttime: i32,
-    },
     // https://github.com/SerenityOS/serenity/blob/ba776390b5878ec0be1a9e595a3471a6cfe0a0cf/Userland/Libraries/LibC/sys/time.h#L19-L22
-    .serenity => extern struct {
+    .dragonfly, .freebsd, .netbsd, .openbsd, .haiku, .illumos, .serenity, .driverkit, .ios, .maccatalyst, .macos, .tvos, .visionos, .watchos, .windows, .wasi => extern struct {
         minuteswest: c_int,
         dsttime: c_int,
     },
diff --git a/lib/std/os/emscripten.zig b/lib/std/os/emscripten.zig
index 648407b20cf187f44ccf74234ed1b0621d206039..ba4d9082a00093a73160242aad84fcf4feabdd58 100644
--- a/lib/std/os/emscripten.zig
+++ b/lib/std/os/emscripten.zig
@@ -730,7 +730,7 @@ pub const sockaddr = c.sockaddr;
 pub const blksize_t = i32;
 pub const nlink_t = u32;
 // https://github.com/emscripten-core/emscripten/blob/946ab574ae39401b51e75cd5257d894ae732ab54/system/lib/libc/musl/arch/emscripten/bits/alltypes.h#L140
-pub const time_t = i64;
+pub const time_t = c_longlong;
 pub const mode_t = u32;
 pub const off_t = i64;
 pub const ino_t = u64;
@@ -766,29 +766,22 @@ pub const stack_t = extern struct {
     size: usize,
 };
 
+/// For use with `utimensat` and `futimens`.
+// https://github.com/emscripten-core/emscripten/blob/d72d7226f4733af8ff993dec70198cf09a24142d/system/lib/libc/musl/include/sys/stat.h#L77-L78
+pub const UTIME = struct {
+    pub const NOW: timespec = .{ .sec = 0, .nsec = 0x3fffffff };
+    pub const OMIT: timespec = .{ .sec = 0, .nsec = 0x3ffffffe };
+};
+
 // https://github.com/emscripten-core/emscripten/blob/946ab574ae39401b51e75cd5257d894ae732ab54/system/lib/libc/musl/arch/emscripten/bits/alltypes.h#L284
 pub const timespec = extern struct {
     sec: time_t,
-    nsec: isize,
-
-    // https://github.com/emscripten-core/emscripten/blob/d72d7226f4733af8ff993dec70198cf09a24142d/system/lib/libc/musl/include/sys/stat.h#L77-L78
-
-    /// For use with `utimensat` and `futimens`.
-    pub const NOW: timespec = .{
-        .sec = 0,
-        .nsec = 0x3fffffff,
-    };
-
-    /// For use with `utimensat` and `futimens`.
-    pub const OMIT: timespec = .{
-        .sec = 0,
-        .nsec = 0x3ffffffe,
-    };
+    nsec: c_long,
 };
 
 pub const timezone = extern struct {
-    minuteswest: i32,
-    dsttime: i32,
+    minuteswest: c_int,
+    dsttime: c_int,
 };
 
 pub const utsname = extern struct {
diff --git a/lib/std/os/linux.zig b/lib/std/os/linux.zig
index 9cd050d8cda42b2a57e80bc3f3f704602f4fe196..12b3e482b51d41a48cfe836f5e45a1a4b1c368c0 100644
--- a/lib/std/os/linux.zig
+++ b/lib/std/os/linux.zig
@@ -5950,11 +5950,6 @@ pub const S = struct {
     }
 };
 
-pub const UTIME = struct {
-    pub const NOW = 0x3fffffff;
-    pub const OMIT = 0x3ffffffe;
-};
-
 const TFD_TIMER = packed struct(u32) {
     ABSTIME: bool = false,
     CANCEL_ON_SET: bool = false,
@@ -8705,22 +8700,16 @@ pub const kernel_timespec = extern struct {
     };
 };
 
+/// For use with `utimensat` and `futimens`.
+pub const UTIME = struct {
+    pub const NOW: timespec = .{ .sec = 0, .nsec = 0x3fffffff };
+    pub const OMIT: timespec = .{ .sec = 0, .nsec = 0x3ffffffe };
+};
+
 // https://github.com/ziglang/zig/issues/4726#issuecomment-2190337877
 pub const timespec = if (native_arch == .hexagon or native_arch == .riscv32) kernel_timespec else extern struct {
     sec: isize,
     nsec: isize,
-
-    /// For use with `utimensat` and `futimens`.
-    pub const NOW: timespec = .{
-        .sec = 0,
-        .nsec = 0x3fffffff,
-    };
-
-    /// For use with `utimensat` and `futimens`.
-    pub const OMIT: timespec = .{
-        .sec = 0,
-        .nsec = 0x3ffffffe,
-    };
 };
 
 pub const XDP = struct {
diff --git a/lib/std/posix.zig b/lib/std/posix.zig
index 36e038c6414ecffa6a46ce694452bb01ae0cc7cb..39d226613733c20497b21ebecfacfed9481d6704 100644
--- a/lib/std/posix.zig
+++ b/lib/std/posix.zig
@@ -174,6 +174,7 @@ pub const timespec = system.timespec;
 pub const timestamp_t = system.timestamp_t;
 pub const timeval = system.timeval;
 pub const timezone = system.timezone;
+pub const UTIME = system.UTIME;
 pub const uid_t = system.uid_t;
 pub const user_desc = system.user_desc;
 pub const utsname = system.utsname;