calamares/CMakeModules/CMakeDateStamp.cmake

find_program(DATE_EXECUTABLE NAMES date)
mark_as_advanced(DATE_EXECUTABLE)

if(DATE_EXECUTABLE)
  execute_process(
    COMMAND ${DATE_EXECUTABLE} +%Y
    OUTPUT_VARIABLE CMAKE_DATESTAMP_YEAR
    OUTPUT_STRIP_TRAILING_WHITESPACE
    WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
  )
  execute_process(
    COMMAND ${DATE_EXECUTABLE} +%m
    OUTPUT_VARIABLE CMAKE_DATESTAMP_MONTH
    OUTPUT_STRIP_TRAILING_WHITESPACE
    WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
  )
  execute_process(
    COMMAND ${DATE_EXECUTABLE} +%d
    OUTPUT_VARIABLE CMAKE_DATESTAMP_DAY
    OUTPUT_STRIP_TRAILING_WHITESPACE
    WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
  )
endif()