tiennm99
18020e2419
Replace the six DragValue spinboxes (year/month/day/hour/minute/second) with a single datetime button that opens one popup containing: - month-navigable calendar grid (chevrons clamp at MIN_YEAR-01 / MAX_YEAR-12) - 6x7 day grid via chrono::NaiveDate arithmetic; out-of-month cells dimmed and jump-to-month on click; today gets a 1px outline; selected day filled - HH:MM:SS DragValues for time (same control style as before) - quick-select row: Now / Midnight / Noon / -1d / +1d - right-aligned Apply primary action; Esc and click-outside close without committing (CloseOnClickOutside + manual Esc capture) Top bar reduces to [Mock Time] [datetime ▼] [Now] Δ = +X.Xs. The Set button is gone — Apply (inside the popup) is the only commit path now. picker_view_year/month is decoupled from fake_*, so chevroning months does not move the selection; opening the popup re-syncs the view to the current fake_year/month. Drop the now-dead pub(crate) fn days_in_month and its 10 tests — the new calendar grid uses chrono's Duration::days and cell_date.day() directly, both of which are self-clamping. apply_fake_time, picked_naive_dt, unix_micros_to_filetime_ticks, and the DST/overflow status_msg flow are unchanged.
TimeMocker
A Windows tool that injects fake time into running processes by hooking Win32 time APIs. Written in Rust.
Status: Active development. This is the canonical implementation. Language-specific ports are available in C# (EasyHook) and C++ (MS Detours).
Architecture
time-mocker-rs/
├── crates/
│ ├── time-mocker-core/ — shared types (MockTimeInfo) + named MMF helper + tick conversions
│ ├── time-mocker-hook/ — cdylib injected into target processes; hooks 5 time APIs via retour
│ ├── time-mocker-test-target/ — console binary that prints all 5 hooked APIs in a loop (dedicated dev target)
│ └── time-mocker-ui/ — egui controller binary; injects via dll-syringe, writes delta per PID
Hooked APIs
| API | DLL |
|---|---|
GetSystemTime |
kernel32 |
GetLocalTime |
kernel32 |
GetSystemTimeAsFileTime |
kernel32 |
GetSystemTimePreciseAsFileTime |
kernel32 |
NtQuerySystemTime |
ntdll |
IPC Design
Named Memory-Mapped File per injected process:
Name: Global\TimeMocker_<PID> (preferred — requires elevation)
Local\TimeMocker_<PID> (fallback — same-session, unelevated dev)
Size: 8 bytes
[0..7] DeltaTicks (i64 — 100-ns units, added to the real FILETIME)
The UI tries Global\ first and falls back to Local\ on ERROR_ACCESS_DENIED
(i.e. when the controller is not elevated and the token lacks
SeCreateGlobalPrivilege). The hook DLL probes both names. Release builds
embed a UAC manifest, so they always get Global\; debug builds run
unelevated and use Local\ for same-session targets.
The hook reads the delta on every time API call and returns real_filetime + delta. The controller writes the delta whenever the user picks a new fake time.
Tick epoch difference vs the C# version: The C# version stores a delta against
DateTime.UtcNow.Ticks(epoch 0001-01-01 UTC). The Rust version stores a delta in raw FILETIME units (epoch 1601-01-01 UTC). The two IPC contracts are not interoperable — the Rust UI and Rust hook DLL only talk to each other.
Build
# Nightly Rust (required by retour for inline x64 detours)
# A `rust-toolchain.toml` at the repo root pins the channel automatically.
cargo build --release
# Outputs:
# target/release/time_mocker_ui.exe
# target/release/time_mocker_hook.dll (must be next to the UI exe)
Requirements
- Windows 10/11 x64
- Rust nightly (pinned via
rust-toolchain.toml) - Release build: must run as Administrator (UAC manifest embedded; needed for
Global\MMF and cross-session injection) - Debug build (
cargo run): runs unelevated; falls back toLocal\namespace — same-session targets only
Dev workflow: test target
Inject into a dedicated harness instead of arbitrary running processes:
# Terminal 1 — start the target, note the PID it prints
cargo run -p time-mocker-test-target
# Terminal 2 — start the UI; type that PID into "Inject by PID"
cargo build --workspace ; cargo run -p time-mocker-ui
The target prints all 5 hooked APIs (GetSystemTime, GetLocalTime,
GetSystemTimeAsFileTime, GetSystemTimePreciseAsFileTime,
NtQuerySystemTime) every second. When the hook is loaded and you set a
fake time in the UI, all five rows shift by the same delta — that's your
proof the hook is live.
License
Apache-2.0 — see LICENSE.
Related
- time-mocker-csharp — C# / EasyHook implementation
- time-mocker-cpp — C++ / MS Detours implementation