diff --git a/src/lib/buzz_time.zig b/src/lib/buzz_time.zig
new file mode 100644
index 00000000..8497af90
--- /dev/null
+++ b/src/lib/buzz_time.zig
@@ -0,0 +1,32 @@
+const api = @import("buzz_api.zig");
+const std = @import("std");
+
+pub export fn timeNow(ctx: *api.NativeCtx) callconv(.c) c_int {
+    const ts = std.Io.Timestamp.now(ctx.getIo(), .real);
+    const ms = ts.toMilliseconds();
+    ctx.vm.bz_push(.fromDouble(@floatFromInt(ms)));
+    return 1;
+}
+
+pub export fn timeMonotonic(ctx: *api.NativeCtx) callconv(.c) c_int {
+    const ts = std.Io.Timestamp.now(ctx.getIo(), .awake);
+    const ms = ts.toMilliseconds();
+    ctx.vm.bz_push(.fromDouble(@floatFromInt(ms)));
+    return 1;
+}
+
+pub export fn timeCpu(ctx: *api.NativeCtx) callconv(.c) c_int {
+    const ts = std.Io.Timestamp.now(ctx.getIo(), .cpu_process);
+    const ms = ts.toMilliseconds();
+    ctx.vm.bz_push(.fromDouble(@floatFromInt(ms)));
+    return 1;
+}
+
+pub const library = api.BuzzApi(
+    "time",
+    &.{
+        &.{ "now", timeNow },
+        &.{ "monotonic", timeMonotonic },
+        &.{ "cpu", timeCpu },
+    },
+){};
diff --git a/src/lib/static_headers.zig b/src/lib/static_headers.zig
index 4ece9fa0..905bba89 100644
--- a/src/lib/static_headers.zig
+++ b/src/lib/static_headers.zig
@@ -22,6 +22,7 @@ pub const math = Header{ .name = "math", .path = "math.buzz" };
 pub const os = Header{ .name = "os", .path = "os.buzz" };
 pub const serialize = Header{ .name = "serialize", .path = "serialize.buzz" };
 pub const std = Header{ .name = "std", .path = "std.buzz" };
+pub const time = Header{ .name = "time", .path = "time.buzz" };
 pub const testing = Header{ .name = "test", .path = "testing.buzz" };
 
 /// Buzz headers bundled with the compiler/runtime and installed for tooling.
@@ -41,4 +42,5 @@ pub const all = [_]Header{
     serialize,
     std,
     testing,
+    time,
 };
diff --git a/src/lib/static_libraries.zig b/src/lib/static_libraries.zig
index 6463a3c5..d64f59bb 100644
--- a/src/lib/static_libraries.zig
+++ b/src/lib/static_libraries.zig
@@ -30,6 +30,7 @@ pub const all = [_]Library{
     .{ .header = static_headers.os, .zig_path = "buzz_os.zig", .wasm_native = false },
     .{ .header = static_headers.serialize, .zig_path = "buzz_serialize.zig", .wasm_native = true },
     .{ .header = static_headers.std, .zig_path = "buzz_std.zig", .wasm_native = true },
+    .{ .header = static_headers.time, .zig_path = "buzz_time.zig", .wasm_native = false },
     .{ .header = static_headers.testing, .zig_path = null, .wasm_native = false },
 };
 
@@ -98,6 +99,7 @@ fn nativeMethods(comptime library: Library) std.StaticStringMap(buzz_api.NativeF
     if (std.mem.eql(u8, zig_path, "buzz_os.zig")) return checkedNativeMethods(library, @import("buzz_os.zig").library);
     if (std.mem.eql(u8, zig_path, "buzz_serialize.zig")) return checkedNativeMethods(library, @import("buzz_serialize.zig").library);
     if (std.mem.eql(u8, zig_path, "buzz_std.zig")) return checkedNativeMethods(library, @import("buzz_std.zig").library);
+    if (std.mem.eql(u8, zig_path, "buzz_time.zig")) return checkedNativeMethods(library, @import("buzz_time.zig").library);
 
     @compileError("unknown native library path: " ++ zig_path);
 }
diff --git a/src/lib/time.buzz b/src/lib/time.buzz
new file mode 100644
index 00000000..15d7f98f
--- /dev/null
+++ b/src/lib/time.buzz
@@ -0,0 +1,12 @@
+namespace time;
+
+import "buzz:errors";
+
+/// Real-time (wall-clock) in milliseconds since Unix epoch
+export extern fun now() > double;
+
+/// Monotonic clock in milliseconds (never goes backwards for intervals)
+export extern fun monotonic() > double;
+
+/// Cpu time used by the current process in milliseconds
+export extern fun cpu() > double !> errors\UnexpectedError;
diff --git a/tests/behavior/time.buzz b/tests/behavior/time.buzz
new file mode 100644
index 00000000..31118957
--- /dev/null
+++ b/tests/behavior/time.buzz
@@ -0,0 +1,29 @@
+import "buzz:std";
+import "buzz:time";
+import "buzz:os" as os;
+
+test "now returns a positive number" {
+    final now = time\now();
+    std\assert(
+        now > 0,
+        message: "now should be greater than 0"
+    );
+}
+
+test "monotonic increases" {
+    final start = time\monotonic();
+    os\sleep(12.0);
+    final end = time\monotonic();
+    std\assert(
+        end > start,
+        message: "monotonic should increase after sleep"
+    );
+}
+
+test "cpu returns a positive number" {
+    final cpu = time\cpu();
+    std\assert(
+        cpu >= 0,
+        message: "cpu time should be >= 0"
+    );
+}