No point reworking it - it doesn't have an RTC.
That module contains a DS1218 (which handles the switching between the external 5V supply and the on board battery, and blocks the write enable signal to the RAM when the 5V rail starts to fail.)

Either replace with any other 2Kx8 non-volatile SRAM or roll your own module.

The DS1218 can be replaced by any other device (or devices) with the same functions.

Personally I'd probably go for a low power 6116, and then bend up the 5V pin and parallel feed it with 5V (either from the ic socket or a flying lead from elsewhere on the PCB)via a diode, and 3V from a battery, again via a diode.
Downside of that approach is the danger of data corruption if a stray write pulse occurs when the system powers up/down.

RiP wrote on 2020-03-27, 16:34:

Is it possible to rework this clock chip? […]
Show full quote

Is it possible to rework this clock chip?

I think so but have yet to figure out how. From the Datasheet of DS1220Y "The DS1220Y 16k Nonvolatile SRAM is a 16,384-bit, fully static, nonvolatile RAM organized as 2048 words by 8 bits. Each NV SRAM has a self-contained lithium energy source and control circuitry that constantly monitor VCC for an out-of-tolerance condition. "
https://www.mouser.com/datasheet/2/256/DS1220Y-263832.pdf
Being unavailable (like a DS1587s) think there must be a way to add external batts, have done it with a 1587. Unlike most Dallas chips with onboard battery, yours does not have blank (or NC) pins so figuring out how or where to add an ext. batt will be a bit more complicated. Maybe some one else has already figured it out but would suggest you wait on trying to mod it until brighter minds come to a consensus. Yes it is fixable !

added: sorry mdog69, but the DS1220y is different than the DS1218.

Horun wrote on 2020-03-28, 01:59:

I think so but have yet to figure out how. From the Datasheet of DS1220Y "The DS1220Y 16k Nonvolatile SRAM is a 16,384-bit, full […]
Show full quote

RiP wrote on 2020-03-27, 16:34:

Is it possible to rework this clock chip? […]
Show full quote

Is it possible to rework this clock chip?

I think so but have yet to figure out how. From the Datasheet of DS1220Y "The DS1220Y 16k Nonvolatile SRAM is a 16,384-bit, fully static, nonvolatile RAM organized as 2048 words by 8 bits. Each NV SRAM has a self-contained lithium energy source and control circuitry that constantly monitor VCC for an out-of-tolerance condition. "
https://www.mouser.com/datasheet/2/256/DS1220Y-263832.pdf
Being unavailable (like a DS1587s) think there must be a way to add external batts, have done it with a 1587. Unlike most Dallas chips with onboard battery, yours does not have blank (or NC) pins so figuring out how or where to add an ext. batt will be a bit more complicated. Maybe some one else has already figured it out but would suggest you wait on trying to mod it until brighter minds come to a consensus. Yes it is fixable !

added: sorry mdog69, but the DS1220y is different than the DS1218.

Thanks, fingers crossed...
It's for this card which loses settings everytime I turn on computer:
Procom Technology ISA SCSI Xelerator