time is always constant(current international time) while calculating the age. this is a GUI version and you dont need extra packages to use this application. Just download, run and enjoy.
Open terminal and run,
git clone https://github.com/mursalatul/Age_Calculator.git
cd Age_Calculator
python age_calculator.py (windows)
python3 age_calculator.py (max/linux)
In some linux distro tkinter is not installed by default. In that case install tk