z/VM and related subsystems to report correct time

ll human-readable (i.e. non-TOD format) date and time values generated by CP, CMS, GCS, REXX, DVF, TCP/IP, RACF, RSCS, and Performance Toolkit components of z/VM must be correct, where "correct" is defined by "UTC plus the time zone offset when the TOD clock is on the z/Architecture-defined standard epoch".

It should be noted that calculation of UTC (current and historical) requires the program to know how many leap seconds are contained within the TOD clock, value AND the TOD clock value when each leap second was introduced to UTC.

This includes, but is not limited to:
CP TERMINAL TIMESTAMP output
CP QUERY TIME
CP DIAGNOSE X'0C' and X'270'
CP ADSR (symptom record)
REXX date() and time() functions
CMS and GCS files
CMS NOTE headers and netlog
CMS DateTimeGet(), DateTimeSubtract(), and other routines that convert to or from TOD format
CMS OS/DOS simulation of the TIME macro
DVF macros that convert TOD clock values from trace entries or other control blocks to non-TOD format

In addition to z/VM's own time-rendering interfaces, when STP is being used, it must provide the necessary support to enable Linux and other TOD-based operating systems to calculate the correct local time when the guest TOD is on the standard epoch without having to run a time-synchronization program such ntpd. Note that this is not a request to virtualize STP, though that may be the preferred solution.

Comments from the review period on share.org:
- For the sake of completeness, and consistent of output, perhaps add &DATE and &TIME output from EXEC classic, and EXEC2.
- I'd be afraid that including &DATE and &TIME from EXEC and EXEC2 might break something. Does anybody write anything in either of these today?