/root/fattime_host.c: In function 'main':
/root/fattime_host.c:176:10: warning: unused variable 's2107' [-Wunused-variable]
  int64_t s2107 = 4354761599LL; /* 2107-12-31 23:59:59 minus odd sec */
          ^~~~~
=== A: round-trip every day 1980-01-01 .. 2107-12-31 ===
first round-trip failure         4295030400.000000000  2106-02-08 00:00:00 UTC
total failing days (of 46699): 692
encoded dd=ff9f t=2800 (y=2107 m=12 d=31)
2107-12-31 decodes to              59783504.000000000  1971-11-23 22:31:44 UTC
=== B: write path, post-2107 tv_sec (utimes, no upper bound) ===
in                                  4354819200.000000000  2108-01-01 00:00:00 UTC
    -> dd=0021 dt=0000 ->                                   315532800.000000000  1980-01-01 00:00:00 UTC
in                                 68718441600.000000000  4147-08-08 08:00:00 UTC
    -> dd=eef8 dt=4000 ->                                  4088563200.000000000  2099-07-24 08:00:00 UTC
in                                103072070400.000000000  5236-03-22 18:40:00 UTC
    -> dd=705c dt=9500 ->                                  2087836800.000000000  2036-02-28 18:40:00 UTC
in                              140737488355327.000000000  4461763-06-20 05:22:07 UTC
    -> dd=5777 dt=2ac3 ->                                  1700716927.000000000  2023-11-23 05:22:07 UTC
in                              4611686018427387904.000000000  2023-11-00 00:32767:-2107336 UTC
    -> dd=f450 dt=3da2 ->                                  4169519104.000000000  2102-02-16 07:45:04 UTC
=== C: crafted dd/dt fields (month 0/13-15, hh=31, mm=63) ===
dd=ff9f dt=bf7d dh=00 ->                                    59851902.000000000  1971-11-24 17:31:42 UTC
    nsec in [0,1e9)? YES
dd=fe0f dt=0000 dh=00 ->                                  4229798400.000000000  2104-01-15 00:00:00 UTC
    nsec in [0,1e9)? YES
dd=ffaf dt=0000 dh=00 ->                                    61061504.000000000  1971-12-08 17:31:44 UTC
    nsec in [0,1e9)? YES
dd=ffff dt=0000 dh=00 ->                                  4231180800.000000000  2104-01-31 00:00:00 UTC
    nsec in [0,1e9)? YES
dd=0021 dt=ffff dh=ff ->                                   315648244.550000000  1980-01-02 08:04:04 UTC
    nsec in [0,1e9)? YES
=== D: day=0 (known DF-0199) ===
day 0 decodes to                  347068800.000000000  1980-12-31 00:00:00 UTC