Calendar module in Pike 8.0 is broken near 1900-01-01T00:00:00 in some timezones.
$ TZ=UTC pike
Pike v8.0 release 1738 running Hilfe v3.5 (Incremental Pike Frontend)
> Calendar.dwim_time("19000101T000000");
(1) Result: Second(Mon 1 Jan 1900 0:00:00 UTC)
$ TZ=Europe/Stockholm pike
Pike v8.0 release 1738 running Hilfe v3.5 (Incremental Pike Frontend)
> Calendar.dwim_time("19000101T000000");
Failed to dwim time from "19000101T000000"
/usr/lib64/pike/modules/Calendar.pmod/YMD.pike:3303:
ISO.dwim_time("19000101T000000",UNDEFINED)
> Calendar.dwim_time("19000101T000013");
Failed to dwim time from "19000101T000013"
/usr/lib64/pike/modules/Calendar.pmod/YMD.pike:3303:
ISO.dwim_time("19000101T000013",UNDEFINED)
> Calendar.dwim_time("19000101T000014");
(1) Result: Second(Mon 1 Jan 1900 0:00:00 CET)
> Calendar.dwim_time("18991231T23:59:59");
(2) Result: Second(Sun 31 Dec 1899 23:59:59 SET)
> Calendar.dwim_time("19000101T000015");
(3) Result: Second(Mon 1 Jan 1900 0:00:01 CET)
Note that when the parsing succeeds, the resulting seconds count is off by 14 seconds.
The above works fine in Pike 9.0 (aka master):
$ TZ=Europe/Stockholm ./pike
Pike v9.0 release 0 running Hilfe v3.5 (Incremental Pike Frontend)
> Calendar.dwim_time("19000101T000000");
(1) Result: Second(Mon 1 Jan 1900 0:00:00 CET)