@hek right 
sizeof uint32_t : 4
it works with :
#define EEPROM_SLEEP_DURATION_ADDRESS 0
uint32_t sleepDurationInS = 86399;
hwWriteConfigBlock((void*)&sleepDurationInS, (void*)(EEPROM_LOCAL_CONFIG_ADDRESS+EEPROM_SLEEP_DURATION_ADDRESS), 4);
hwReadConfigBlock((void*)&sleepDurationInS, (void*)(EEPROM_LOCAL_CONFIG_ADDRESS+EEPROM_SLEEP_DURATION_ADDRESS), 4);
@tekka Hi, I found my mistake ! You were absolutely right when you said there is no sign of MYSBootloader in my GW log...
But now I know why :
I use an USBasp Programmer with Arduino IDE for upload my bootloader and my sketch..., and I mistakenly thought that when I upload bootloader then sketch, it keep bootloader.....but NOT, it overwrite bootloader 
I fix it by uploading the xxx.with_bootloader.hex file generated by Arduino IDE when compile.
Sorry for the inconvenience and thank you for your help