The coming change for HP 3000 date-keeping is a product of the computer's operating system. The hardware will run as it always has, no matter how far ahead calendars and dates reach into the future. Even into the year 2028 and beyond. For some users, they're heard about this as the "2027 problem."
The CALENDAR problem is in the OS, not the hardware. The old intrinsic was only built to record accurate dates until the end of 2027. Any resolution will involve work within applications' use of intrinsics, among other software revisions. Replacing CALENDAR with HPCALENDAR is part of the solution. Charon sites will have to prepare for it too, because they are running faithful virtualizations of the PA-RISC hardware — and use MPE/iX
Hardware vs. software in 2028 is a common misunderstanding in the 3000 community. Everyone figures the Hewlett-Packard 3000 hardware, pushing 20-25 years in service in most places even today, won't be able to keep up. It's not the PA-RISC chips that will make a mistake identifying the correct year, though. It's MPE/iX.
There's a way around this aging software intrinsic: replacement. HP built a perfectly serviceable improvement of calendar intrinsics, HPCALENDAR, when it became obvious the 3000 community was going to go well past the Year 2000. HPCALENDAR isn't wired into the OS's roots, though. SHOWTIME, for example, is always going to report an incorrect year starting the first day of 2028.
Applications that can be revised to use HPCALENDAR will stream jobs on correct dates. Native job-streaming service in MPE/iX will work if a command uses a request such as "three days from now." In general, the more closely a piece of MPE/iX software relies on CALENDAR, the less likely it will be to deliver accurate dates starting in 2028.
Source code revision will be the most direct solution in some cases. Support companies are assembling certification services for Year 2028 operations. It's a place the 3000 community has worked through before now. We all remember how Y2K didn't halt 3000s. Developers, vendors, and support experts all say that 2028 is nothing as serious as Y2K was — so long as customers are aware of it and prepare.
We put together an FAQ about 2028 last year after vendors and users starting talking about the CALENDAR impact. It's worth a look and perhaps a forward to your support team if their answers are "that's a 3000 thing with HP's hardware" or they don't know how the year 2027 will end for MPE/iX. In December of that year, dates that are supposed to be reported at 2028 will say 1900. There's a strategy to repair that.