As you can check 43xxx_Wi-Fi/WICED/platform/MCU/BCM4390x/peripherals/platform_hib.c, you will find that ticks_to_wakeup is of datatype uint32_t which means it can only take a value till (2^32 - 1). When the platform is put into hibernation mode, basically a counter is started from 0 to the ticks count provided (based on the internal or external hib clock selection you can get the timing which you have reported to be 37 hours).
Could you please tell why you want the chip to be in hibernation forever? HIB means essentially only that part of the chip is ON and even the PMU is powered down so none of the Wi-Fi/Apps related functionalities will be available.
