Unfortunately, I’m not the owner or maintainer of this project.
So here is a snippet of code:
/*
* Convert the compilation (build) date from a string literal of
* the form "Mmm dd ccyy" to Binary Coded Decimal.
*/
#define __MONTH_H__ ((__DATE__[0] + __DATE__[1] + __DATE__[2]) == 0x119 ? 0x0 : \
(__DATE__[0] + __DATE__[1] + __DATE__[2]) == 0x10d ? 0x0 : \
(__DATE__[0] + __DATE__[1] + __DATE__[2]) == 0x120 ? 0x0 : \
(__DATE__[0] + __DATE__[1] + __DATE__[2]) == 0x123 ? 0x0 : \
(__DATE__[0] + __DATE__[1] + __DATE__[2]) == 0x127 ? 0x0 : \
(__DATE__[0] + __DATE__[1] + __DATE__[2]) == 0x12d ? 0x0 : \
(__DATE__[0] + __DATE__[1] + __DATE__[2]) == 0x12b ? 0x0 : \
(__DATE__[0] + __DATE__[1] + __DATE__[2]) == 0x11d ? 0x0 : \
(__DATE__[0] + __DATE__[1] + __DATE__[2]) == 0x128 ? 0x0 : \
(__DATE__[0] + __DATE__[1] + __DATE__[2]) == 0x126 ? 0x10 : \
(__DATE__[0] + __DATE__[1] + __DATE__[2]) == 0x133 ? 0x10 : \
(__DATE__[0] + __DATE__[1] + __DATE__[2]) == 0x10c ? 0x10 : \
0)
#define __MONTH_L__ ((__DATE__[0] + __DATE__[1] + __DATE__[2]) == 0x119 ? 0x1 : \
(__DATE__[0] + __DATE__[1] + __DATE__[2]) == 0x10d ? 0x2 : \
(__DATE__[0] + __DATE__[1] + __DATE__[2]) == 0x120 ? 0x3 : \
(__DATE__[0] + __DATE__[1] + __DATE__[2]) == 0x123 ? 0x4 : \
(__DATE__[0] + __DATE__[1] + __DATE__[2]) == 0x127 ? 0x5 : \
(__DATE__[0] + __DATE__[1] + __DATE__[2]) == 0x12d ? 0x6 : \
(__DATE__[0] + __DATE__[1] + __DATE__[2]) == 0x12b ? 0x7 : \
(__DATE__[0] + __DATE__[1] + __DATE__[2]) == 0x11d ? 0x8 : \
(__DATE__[0] + __DATE__[1] + __DATE__[2]) == 0x128 ? 0x9 : \
(__DATE__[0] + __DATE__[1] + __DATE__[2]) == 0x126 ? 0x0 : \
(__DATE__[0] + __DATE__[1] + __DATE__[2]) == 0x133 ? 0x1 : \
(__DATE__[0] + __DATE__[1] + __DATE__[2]) == 0x10c ? 0x2 : \
0)
#define __CENTURY__ (((__DATE__[7] - '0') << 4) + (__DATE__[8] - '0'))
#define __YEAR__ (((__DATE__[9] - '0') << 4) + (__DATE__[10] - '0'))
#define __DAY__ (((__DATE__[4] - '0') << 4) + (__DATE__[5] - '0'))
#define __MONTH__ (__MONTH_H__ + __MONTH_L__)
#if 0
/*
* The Auxiliary Firmware Revision Information field is optional. If present,
* it holds additional information about the firmware revision, such as boot
* block or internal data structure version numbers.
* The meanings of the numbers are specific to the vendor identified
* by Manufacturer ID.
*/
#define CFG_APP_FIRMWARE_AUX_REV1 __CENTURY__
#define CFG_APP_FIRMWARE_AUX_REV2 __YEAR__
#define CFG_APP_FIRMWARE_AUX_REV3 __MONTH__
#define CFG_APP_FIRMWARE_AUX_REV4 __DAY__
#endif