timeskew.exe lets you accelerate the system time for specific programs.
This project is the Windows equivalent of timeskew,
which works on Linux (using LD_PRELOAD).
Compare the output of:
> python test.py
and:
> SET TIMESKEW="10 1" && timeskew python test.py
This will continuously display the currently date and time every second. The second one will go 10 times faster and quickly display times in the future.
If you do not have Python installed, you can use the Batch and PowerShell test scripts instead.
The behavior can be controlled with environment variables:
| Name | Example | Effect |
|---|---|---|
| TIMESKEW | 10 1 |
Set relative time speed to ×10 |
| TIMESKEW | 1 2 |
Set relative time speed to ÷2 |
| TIMESKEW_LOGFILE | - |
Log calls to modified WINAPI functions to stdout |
| TIMESKEW_LOGFILE | timeskew.log |
Log calls to modified WINAPI functions to timeskew.log |
| TIMESKEW_PORT | 40000 |
Listen on TCP port 40000 for updates to relative time speed |
To control the relative time speed while the application is running, start it with TIMESKEW_PORT set to a free port number.
Then, assuming Nmap is installed, run:
> ncat -v 127.0.0.1 40000
10 1
Instead of Nmap/Ncat, you can use telnet, although it is not installed on Windows by default anymore.
First, clone the repository and its dependencies:
> git clone --recursive https://github.com/qsantos/timeskew.exe
Note:
If you forget the --recursive option when cloning the repository, use git submodule --init --recursive
Then, you will need to install the installer for the Visual Studio build tools, and use it to install:
- “Desktop development with C++”, with the optional “MSVC” and “Windows 11 SDK”
- “.NET desktop development”
Once this is done, open the “Developer Command Prompt” or “Developer PowerShell”, navigate to the repository, and run:
> nmake
This project uses Detours,
which is similar to LD_PRELOAD on the (at least for the WINAPI).
To see how this works, look at the corresponding documentation.
timeskew.exe uses Detours to intercepts calls to all WINAPI functions that involve time (that I know of).
To simulation the acceleration of time,
inputs (e.g. for Sleep) are reduced proportionally,
while outputs are increased proportionally (for instance GetSystemTime).