Howard Hinnant's Date library (https://howardhinnant.github.io/date/date.html) was used to provide real time stamps for logging instead of the number of milliseconds since the start of a certain OS-dependent epoch.

The central LICENSE.TXT in the project states the following:

The source code in this project is released using the MIT License. There is no
global license for the project because each file is licensed individually with
different author names and/or dates.

If you contribute to this project, please add your name to the license of each
file you modify.  If you have already contributed to this project and forgot to
add your name to the license, please feel free to submit a new P/R to add your
name to the license in each file you modified.

Since only a header-based set of functionality from date.h is used, the following license applies:

The MIT License (MIT)

Copyright (c) 2015, 2016, 2017 Howard Hinnant
Copyright (c) 2016 Adrian Colomitchi
Copyright (c) 2017 Florian Dang
Copyright (c) 2017 Paul Thompson
Copyright (c) 2018, 2019 Tomasz Kamiński
Copyright (c) 2019 Jiangang Zhuang

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

Our apologies.  When the previous paragraph was written, lowercase had not yet
been invented (that would involve another several millennia of evolution).
We did not mean to shout.

Used version

The following table lists which version of Impact Acquire does use which version of Howard Hinnant's date and time library.

Impact Acquire version	Date library version	CPE name
since 3.0.0	3.0.1