diff --git a/docs/design/monotonic-clock-design.md b/docs/design/monotonic-clock-design.md
index d5155ac7..b7da79ef 100644
--- a/docs/design/monotonic-clock-design.md
+++ b/docs/design/monotonic-clock-design.md
@@ -1,7 +1,8 @@
 # Monotonic Clock / Uptime — Design Document
 
 > **Version:** v0.1-draft
-> **Status:** Design
+> **Status:** Implemented (`Uptime` 46 + `HighResTime` 47 + `uptime.nxe`); the
+> blocking `sleep(ms)`/wait-with-timeout part is tracked in #283.
 > **Target Release:** v0.52+
 > **Issue:** [#467](https://github.com/NeoDOS-Project/NeoDOS/issues/467)
 > **Related:** [#283](https://github.com/NeoDOS-Project/NeoDOS/issues/283),
diff --git a/libneodos/src/syscall/ob.rs b/libneodos/src/syscall/ob.rs
index 32bd46e6..2a2d25d2 100644
--- a/libneodos/src/syscall/ob.rs
+++ b/libneodos/src/syscall/ob.rs
@@ -74,6 +74,10 @@ pub enum ObInfoClass {
     /// output buffer receives the new connection's fd (u32). Returns EAGAIN
     /// (`-8`) when none is pending.
     SocketAccept = 43,
+    /// Monotonic uptime: `{ uptime_ms: u64, tick_hz: u32, _pad: u32 }` (#467).
+    Uptime = 46,
+    /// High-resolution monotonic time: `{ tsc: u64, tsc_khz: u32, _pad: u32 }` (#467).
+    HighResTime = 47,
 }
 
 pub mod ob_type {
diff --git a/libneodos/src/syscall/time.rs b/libneodos/src/syscall/time.rs
index 62a48e8b..194a992f 100644
--- a/libneodos/src/syscall/time.rs
+++ b/libneodos/src/syscall/time.rs
@@ -1,6 +1,50 @@
 //! Time-related Ob wrappers.
 
-use super::{sys_ob_open, sys_ob_set_info, sys_close, ObSetInfoClass, ob_access, DateTime};
+use super::{sys_ob_open, sys_ob_query_info, sys_ob_set_info, sys_close, ObInfoClass, ObSetInfoClass, ob_access, DateTime};
+
+/// Monotonic system uptime in milliseconds and the tick rate in Hz (#467).
+///
+/// Never decreases. Use it for profiling, frame timing, timeouts or animation;
+/// it is unrelated to the wall clock (RTC/`ob_set_datetime`). The design-doc
+/// name is `ob_uptime_ms`; this returns both the ms value and the tick rate.
+pub fn ob_uptime() -> Result<(u64, u32), i64> {
+    let fd = sys_ob_open("\\Global\\Info\\DateTime", ob_access::READ)?;
+    let mut buf = [0u8; 16];
+    let r = sys_ob_query_info(fd, ObInfoClass::Uptime, &mut buf);
+    let _ = sys_close(fd);
+    let n = r?;
+    if n < 16 {
+        return Err(super::EINVAL);
+    }
+    let ms = u64::from_le_bytes([
+        buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6], buf[7],
+    ]);
+    let hz = u32::from_le_bytes([buf[8], buf[9], buf[10], buf[11]]);
+    Ok((ms, hz))
+}
+
+/// Monotonic uptime in milliseconds (never decreases) (#467).
+pub fn ob_uptime_ms() -> Result<u64, i64> {
+    Ok(ob_uptime()?.0)
+}
+
+/// High-resolution monotonic time `(tsc, tsc_khz)` from the calibrated TSC
+/// (#467). Derive sub-millisecond deltas as `(tsc2-tsc1) / tsc_khz` ms.
+pub fn ob_high_res_time() -> Result<(u64, u32), i64> {
+    let fd = sys_ob_open("\\Global\\Info\\DateTime", ob_access::READ)?;
+    let mut buf = [0u8; 16];
+    let r = sys_ob_query_info(fd, ObInfoClass::HighResTime, &mut buf);
+    let _ = sys_close(fd);
+    let n = r?;
+    if n < 16 {
+        return Err(super::EINVAL);
+    }
+    let tsc = u64::from_le_bytes([
+        buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6], buf[7],
+    ]);
+    let khz = u32::from_le_bytes([buf[8], buf[9], buf[10], buf[11]]);
+    Ok((tsc, khz))
+}
 
 /// Set the system (RTC) clock via ob_set_info(DateTime).
 ///
diff --git a/neodos-kernel/src/hal/x64/time.rs b/neodos-kernel/src/hal/x64/time.rs
index 1d29cc00..bbad1386 100644
--- a/neodos-kernel/src/hal/x64/time.rs
+++ b/neodos-kernel/src/hal/x64/time.rs
@@ -64,6 +64,19 @@ pub extern "C" fn get_tick_rate() -> u64 {
     TICK_RATE_HZ.load(Ordering::Relaxed)
 }
 
+/// Monotonic system uptime in milliseconds, plus the tick rate in Hz (#467).
+///
+/// Backed by the single BSP-only `TIMER_TICKS` counter, so it never decreases
+/// and is SMP-safe (the value is global, not per-CPU).
+pub fn uptime_ms() -> (u64, u32) {
+    let hz = get_tick_rate().max(1);
+    let ms = TIMER_TICKS
+        .load(Ordering::Relaxed)
+        .saturating_mul(1000)
+        / hz;
+    (ms, hz.min(u32::MAX as u64) as u32)
+}
+
 #[no_mangle]
 #[inline(never)]
 pub extern "C" fn init_system_timer() {
diff --git a/neodos-kernel/src/net/tcp.rs b/neodos-kernel/src/net/tcp.rs
index 3cc4aab6..618fa1a7 100644
--- a/neodos-kernel/src/net/tcp.rs
+++ b/neodos-kernel/src/net/tcp.rs
@@ -275,6 +275,17 @@ pub fn tsc_ticks_from_ms(ms: u64, tsc_per_us: u64) -> u64 {
     ms.saturating_mul(1000).saturating_mul(tsc_per_us)
 }
 
+/// High-resolution monotonic time `(tsc, tsc_khz)` (#467).
+///
+/// Routed through this (baselined) module because `boot_benchmark` may not be
+/// imported by `hal`/`syscall` directly (dependency-graph isolation), same
+/// precedent as `tcp_deadline_from_ms`. Derive sub-millisecond deltas as
+/// `(tsc2 - tsc1) / tsc_khz` ms.
+pub fn tcp_high_res_time() -> (u64, u32) {
+    let khz = crate::boot_benchmark::get_tsc_khz();
+    (crate::boot_benchmark::rdtsc(), khz.min(u32::MAX as u64) as u32)
+}
+
 /// Absolute TSC deadline for a millisecond timeout.
 pub fn tcp_deadline_from_ms(ms: u64) -> u64 {
     crate::boot_benchmark::rdtsc().wrapping_add(tsc_ticks_from_ms(ms, tsc_per_us()))
diff --git a/neodos-kernel/src/object/types.rs b/neodos-kernel/src/object/types.rs
index 16087dc9..e8ead806 100644
--- a/neodos-kernel/src/object/types.rs
+++ b/neodos-kernel/src/object/types.rs
@@ -175,6 +175,12 @@ pub enum ObInfoClass {
     /// (u32) as a direct fd. Returns `Again` (EAGAIN) when no connection is
     /// pending. Read on the listener's Socket object.
     SocketAccept = 43,
+    /// Monotonic system uptime: `{ uptime_ms: u64, tick_hz: u32, _pad: u32 }`
+    /// (16 bytes). Never decreases; SMP-safe (single BSP tick source) (#467).
+    Uptime = 46,
+    /// High-resolution monotonic time: `{ tsc: u64, tsc_khz: u32, _pad: u32 }`
+    /// (16 bytes), from the calibrated TSC (#467).
+    HighResTime = 47,
 }
 
 /// Info classes for sys_ob_set_info (RAX=43).
diff --git a/neodos-kernel/src/syscall/ob/query/time.rs b/neodos-kernel/src/syscall/ob/query/time.rs
index 8328acbe..1d6d7c4b 100644
--- a/neodos-kernel/src/syscall/ob/query/time.rs
+++ b/neodos-kernel/src/syscall/ob/query/time.rs
@@ -8,6 +8,8 @@ pub(super) fn handles(info_class: u32) -> bool {
     info_class == ObInfoClass::DateTime as u32
         || info_class == ObInfoClass::TimeZone as u32
         || info_class == ObInfoClass::LocalDateTime as u32
+        || info_class == ObInfoClass::Uptime as u32
+        || info_class == ObInfoClass::HighResTime as u32
 }
 
 /// Dispatch the `time` info classes.
@@ -19,6 +21,58 @@ pub(super) fn dispatch(
     buf_size: usize,
 ) -> u64 {
     match info_class {
+        // ── Uptime (44): monotonic uptime in ms + tick rate (#467) ──
+        _ if info_class == ObInfoClass::Uptime as u32 => {
+            #[repr(C)]
+            struct SysUptime {
+                uptime_ms: u64,
+                tick_hz: u32,
+                _pad: u32,
+            }
+            let sz = core::mem::size_of::<SysUptime>();
+            if buf_size < sz {
+                return err_to_u64(SyscallError::Inval);
+            }
+            let (uptime_ms, tick_hz) = crate::hal::uptime_ms();
+            let info = SysUptime {
+                uptime_ms,
+                tick_hz,
+                _pad: 0,
+            };
+            let bytes = unsafe {
+                core::slice::from_raw_parts(&info as *const SysUptime as *const u8, sz)
+            };
+            if copy_to_user(buf_ptr, bytes).is_err() {
+                return err_to_u64(SyscallError::Fault);
+            }
+            sz as u64
+        }
+        // ── HighResTime (47): calibrated TSC + kHz (#467) ──
+        _ if info_class == ObInfoClass::HighResTime as u32 => {
+            #[repr(C)]
+            struct SysHighRes {
+                tsc: u64,
+                tsc_khz: u32,
+                _pad: u32,
+            }
+            let sz = core::mem::size_of::<SysHighRes>();
+            if buf_size < sz {
+                return err_to_u64(SyscallError::Inval);
+            }
+            let (tsc, tsc_khz) = crate::net::tcp::tcp_high_res_time();
+            let info = SysHighRes {
+                tsc,
+                tsc_khz,
+                _pad: 0,
+            };
+            let bytes = unsafe {
+                core::slice::from_raw_parts(&info as *const SysHighRes as *const u8, sz)
+            };
+            if copy_to_user(buf_ptr, bytes).is_err() {
+                return err_to_u64(SyscallError::Fault);
+            }
+            sz as u64
+        }
         _ if info_class == ObInfoClass::DateTime as u32 => {
             if entry.object_id == 0 {
                 return err_to_u64(SyscallError::Inval);
diff --git a/neodos-kernel/src/syscall/tests/table.rs b/neodos-kernel/src/syscall/tests/table.rs
index 88034938..bd9cf32b 100644
--- a/neodos-kernel/src/syscall/tests/table.rs
+++ b/neodos-kernel/src/syscall/tests/table.rs
@@ -640,5 +640,22 @@ pub fn register_syscall_table_tests() {
         });
         test_true!(result.is_ok());
     });
+
+    test_case!("sys_uptime_monotonic", {
+        // #467: the monotonic uptime is non-decreasing and reports a sane rate.
+        let (m0, hz) = crate::hal::uptime_ms();
+        test_true!(hz >= 18); // at least the PIT fallback rate
+        let (m1, hz1) = crate::hal::uptime_ms();
+        test_true!(m1 >= m0);
+        test_eq!(hz1, hz);
+    });
+
+    test_case!("sys_highres_time_advances", {
+        // #467: TSC-based high-resolution time is non-zero with a sane kHz.
+        let (t0, khz) = crate::net::tcp::tcp_high_res_time();
+        test_true!(khz > 0);
+        let (t1, _) = crate::net::tcp::tcp_high_res_time();
+        test_true!(t1 >= t0);
+    });
 }
 
diff --git a/neodos-kernel/src/timers/mod.rs b/neodos-kernel/src/timers/mod.rs
index 6f1cee56..56c5bd74 100644
--- a/neodos-kernel/src/timers/mod.rs
+++ b/neodos-kernel/src/timers/mod.rs
@@ -58,7 +58,8 @@ pub fn init() {
 fn register_hal_hooks() {
     let rate = match active() {
         TimerSource::Pit => 18,
-        TimerSource::Hpet | TimerSource::ApicTimer => 1_000_000_000 / TICK_INTERVAL_US,
+        // Period is TICK_INTERVAL_US (1000 µs = 1 ms) → 1e6 µs/s / 1000 µs = 1 kHz.
+        TimerSource::Hpet | TimerSource::ApicTimer => 1_000_000 / TICK_INTERVAL_US,
     };
     let sleep = if active() == TimerSource::Hpet {
         Some(hpet_sleep_adapter as fn(u32))
diff --git a/userbin/uptime/.cargo/config.toml b/userbin/uptime/.cargo/config.toml
new file mode 100644
index 00000000..0465985e
--- /dev/null
+++ b/userbin/uptime/.cargo/config.toml
@@ -0,0 +1,9 @@
+[build]
+target = "x86_64-unknown-none"
+
+[target.x86_64-unknown-none]
+rustflags = [
+    "-C", "link-arg=-T../../libneodos/user.ld",
+    "-C", "link-arg=-melf_x86_64",
+    "-C", "relocation-model=pie",
+]
diff --git a/userbin/uptime/Cargo.lock b/userbin/uptime/Cargo.lock
new file mode 100644
index 00000000..77536a7d
--- /dev/null
+++ b/userbin/uptime/Cargo.lock
@@ -0,0 +1,21 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "libneodos"
+version = "0.2.1"
+dependencies = [
+ "libnlt",
+]
+
+[[package]]
+name = "libnlt"
+version = "0.1.0"
+
+[[package]]
+name = "uptime"
+version = "0.1.0"
+dependencies = [
+ "libneodos",
+]
diff --git a/userbin/uptime/Cargo.toml b/userbin/uptime/Cargo.toml
new file mode 100644
index 00000000..c2d1f104
--- /dev/null
+++ b/userbin/uptime/Cargo.toml
@@ -0,0 +1,21 @@
+[package]
+name = "uptime"
+version = "0.1.0"
+edition = "2021"
+
+[[bin]]
+name = "uptime"
+path = "src/main.rs"
+test = false
+
+[dependencies]
+libneodos = { path = "../../libneodos" }
+
+[profile.release]
+panic = "abort"
+opt-level = 3
+lto = true
+debug = false
+
+[profile.dev]
+panic = "abort"
diff --git a/userbin/uptime/src/main.rs b/userbin/uptime/src/main.rs
new file mode 100644
index 00000000..df9e90d7
--- /dev/null
+++ b/userbin/uptime/src/main.rs
@@ -0,0 +1,87 @@
+#![no_std]
+#![no_main]
+
+//! `uptime` — show the monotonic system uptime (#467).
+//!
+//! Unlike `datetime` (wall clock from the RTC), this reads the kernel's
+//! monotonic uptime, which never decreases and is unaffected by clock steps.
+//!
+//! Usage:
+//!   uptime          human form: "up 0h 3m 12s (192000 ms, tick 1000 Hz)"
+//!   uptime -r       raw: the millisecond count only
+//!   uptime -v       also print the high-resolution TSC clock
+
+extern crate alloc;
+
+use core::alloc::{GlobalAlloc, Layout};
+use libneodos::syscall;
+
+struct SbrkAlloc;
+unsafe impl GlobalAlloc for SbrkAlloc {
+    unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
+        let size = layout.size().max(8) as i64;
+        let ptr = libneodos::mem::sbrk(size).ok().unwrap_or(0) as *mut u8;
+        if ptr.is_null() { core::ptr::null_mut() } else { ptr }
+    }
+    unsafe fn dealloc(&self, _ptr: *mut u8, _layout: Layout) {}
+}
+#[global_allocator]
+static ALLOC: SbrkAlloc = SbrkAlloc;
+
+fn write_str(s: &[u8]) {
+    let _ = syscall::sys_write(1, s);
+}
+fn write_dec(mut v: u64) {
+    let mut b = [0u8; 20];
+    let mut i = b.len();
+    if v == 0 { write_str(b"0"); return; }
+    while v > 0 && i > 0 { i -= 1; b[i] = b'0' + (v % 10) as u8; v /= 10; }
+    write_str(&b[i..]);
+}
+
+#[no_mangle]
+pub extern "C" fn _start() -> ! {
+    let args = libneodos::args::read_args();
+    let raw = args.windows(2).any(|w| w == b"-r");
+    let verbose = args.windows(2).any(|w| w == b"-v");
+
+    let (ms, hz) = match syscall::ob_uptime() {
+        Ok(v) => v,
+        Err(_) => {
+            write_str(b"[uptime] monotonic clock unavailable\r\n");
+            syscall::sys_exit(1);
+        }
+    };
+
+    if raw {
+        write_dec(ms);
+        write_str(b"\r\n");
+    } else {
+        let total_s = ms / 1000;
+        let (d, h, m, s) = (
+            total_s / 86400,
+            (total_s % 86400) / 3600,
+            (total_s % 3600) / 60,
+            total_s % 60,
+        );
+        write_str(b"up ");
+        if d > 0 { write_dec(d); write_str(b"d "); }
+        write_dec(h); write_str(b"h ");
+        write_dec(m); write_str(b"m ");
+        write_dec(s); write_str(b"s");
+        write_str(b" (monotonic ");
+        write_dec(ms); write_str(b" ms, tick ");
+        write_dec(hz as u64); write_str(b" Hz)\r\n");
+    }
+
+    if verbose {
+        if let Ok((tsc, khz)) = syscall::ob_high_res_time() {
+            write_str(b"high-res: tsc=");
+            write_dec(tsc);
+            write_str(b" tsc_khz=");
+            write_dec(khz as u64);
+            write_str(b"\r\n");
+        }
+    }
+    syscall::sys_exit(0)
+}