Return JES2 job timestamps as ISO 8601 UTC

include/jestime.h

@@ -0,0 +1,23 @@
+/* JESTIME.H
+** Render a JES2 job timestamp for a JSON response.
+**
+** Shared by jesst.c (/jes/status, /jes/ddlist) and httpjes2.c, which emitted
+** the same field two ways and both wrong -- see src/jestime.c for why.
+*/
+#ifndef JESTIME_H
+#define JESTIME_H
+
+#include <time64.h>
+
+/* Longest output is "2026-08-07T17:25:18.000Z" plus NUL. */
+#define JESTIME_LEN 32
+
+/* Format *t as an ISO 8601 instant in UTC ("2026-08-07T17:25:18.000Z") into
+** out -- the shape real z/OSMF uses for exec-submitted / exec-started /
+** exec-ended, so this API and mvsMF's stay directly comparable.
+** A zero timestamp (a job that has not started or ended) yields "...", which
+** is what the JSON carried before and what clients already tolerate.
+** out must hold at least JESTIME_LEN bytes. */
+void jestime(const time64_t *t, char *out, unsigned outlen);
+
+#endif /* JESTIME_H */

src/httpjes2.c

@@ -1,7 +1,12 @@
 /* HTTPJES2.C - CGI Program, REST style CGI program for access of JES2 resources */
 #include "httpd.h"
 #include "clibjes2.h"   /* JES prototypes */
+#include "jestime.h"   /* ISO 8601 UTC job timestamps */
 #include "clibcp.h"     /* JES checkpoint struct */
+
+/* libc370 ships __tzget() (src/clib/@@tzget.c) but declares it in no header
+   -- see libc370 #70.  Returns crt->crttzoff for the calling task. */
+extern int __tzget(void);
 
 #define httpx   (httpd->httpx)
 
@@ -130,11 +135,24 @@ do_status(HTTPD *httpd, HTTPC *httpc, const char *jobname, const char *jobid, in
     char        jesinfo[20] = "unknown";
 	time64_t	start_time;
 	time64_t	end_time;
+	char		tbuf[JESTIME_LEN];
 	const char  *smfid;
 
 	httpsecs(&start);
 
-	tzadjust = httpd->tzoffset * -1;	/* change sign as we want to convert local time to GMT */
+	/* JES2 stores its checkpoint timestamps in system local time, so they need
+	** the system's offset to become UTC -- and specifically the SYSTEM's, not
+	** httpd->tzoffset.  That field is a configured preference for httpd's own
+	** local-time rendering (Date: is unaffected, it goes through gmtime64), and
+	** an operator who sets TZOFFSET to their own zone rather than the machine's
+	** would otherwise skew every timestamp this API reports.  These fields are
+	** labelled "Z", so they have to be UTC whatever the Parmlib says.
+	**
+	** __tzget() returns crt->crttzoff for this task, which cgistart's tzset()
+	** filled in from TZ or the system's CVTTZ -- a fact about the machine, not a
+	** setting.  Sign: crttzoff is seconds east of UTC (negative west), and
+	** UTC = local - offset, hence the * -1 to give an addend. */
+	tzadjust = __tzget() * -1;
 
     /* select filtering criteria */
     if (jobname && !jobid) {
@@ -317,21 +335,13 @@ do_status(HTTPD *httpd, HTTPC *httpc, const char *jobname, const char *jobid, in
 #else
         rc = http_printf(httpc, "      \"start_stamp\": \"%llu\",\n", start_time);
         if (rc < 0) goto quit;
-        if (__64_cmp_u32(&start_time, 0) != __64_EQUAL) {
-            rc = http_printf(httpc, "      \"start_display\": \"%-24.24s\",\n", ctime64(&start_time) );
-        }
-        else {
-            rc = http_printf(httpc, "      \"start_display\": \"...\",\n");
-        }
+        jestime(&start_time, tbuf, sizeof(tbuf));
+        rc = http_printf(httpc, "      \"start_display\": \"%s\",\n", tbuf);
         if (rc < 0) goto quit;
         rc = http_printf(httpc, "      \"end_stamp\": \"%llu\",\n", end_time);
         if (rc < 0) goto quit;
-        if (__64_cmp_u32(&end_time, 0) != __64_EQUAL) {
-            rc = http_printf(httpc, "      \"end_display\": \"%-24.24s\",\n", ctime64(&end_time) );
-        }
-        else {
-            rc = http_printf(httpc, "      \"end_display\": \"...\",\n" );
-        }
+        jestime(&end_time, tbuf, sizeof(tbuf));
+        rc = http_printf(httpc, "      \"end_display\": \"%s\",\n", tbuf);
         if (rc < 0) goto quit;
 #endif
         rc = do_status_ddlist(httpd, httpc, j, "      ");

src/jesst.c

@@ -1,6 +1,7 @@
 /* JESST.C - CGI Program, display JOE from JES checkpoint */
 #include "httpd.h"
 #include "clibjes2.h"   /* JES prototypes */
+#include "jestime.h"   /* ISO 8601 UTC job timestamps */
 
 #define httpx   (httpd->httpx)
 
@@ -21,6 +22,7 @@ int main(int argc, char **argv)
     double      start   = 0.0;
     double      end     = 0.0;
     unsigned    n;
+    char        tbuf[JESTIME_LEN];
 #if 0
     struct {
         unsigned short  len;
@@ -123,19 +125,11 @@ int main(int argc, char **argv)
         }
 #else
         printf("      \"start_stamp\": \"%llu\",\n", j->start_time64.u64 );
-        if (__64_cmp_u32(&j->start_time64, 0) != __64_EQUAL) {
-            printf("      \"start_display\": \"%-24.24s\",\n", ctime64(&j->start_time64) );
-        }
-        else {
-            printf("      \"start_display\": \"...\",\n");
-        }
+        jestime(&j->start_time64, tbuf, sizeof(tbuf));
+        printf("      \"start_display\": \"%s\",\n", tbuf);
         printf("      \"end_stamp\": \"%llu\",\n", j->end_time64.u64);
-        if (__64_cmp_u32(&j->end_time64, 0) != __64_EQUAL) {
-            printf("      \"end_display\": \"%-24.24s\",\n", ctime64(&j->end_time64) );
-        }
-        else {
-            printf("      \"end_display\": \"...\",\n" );
-        }
+        jestime(&j->end_time64, tbuf, sizeof(tbuf));
+        printf("      \"end_display\": \"%s\",\n", tbuf);
 #endif
         print_dd(httpd, j, "      ");
         printf("    }%s\n", (n+1) < count ? ",":"");

src/jestime.c

@@ -0,0 +1,64 @@
+/* JESTIME.C
+** Render a JES2 job timestamp for a JSON response, as an ISO 8601 instant in
+** UTC.
+**
+** The field used to be produced by ctime64(), which converts through
+** crt->crttzoff -- the *task's* timezone, filled in from the system's CVTTZ
+** when nothing else set it.  Two things were wrong with that.
+**
+** It applied a second, unrelated offset.  The epoch value beside it comes from
+** the JES2 conversion, which uses httpd->tzoffset; running the same instant
+** through ctime64() then shifted it again by the CRT's offset.  On the
+** reference system (CVTTZ = -5h) a job that started at 17:25:18 UTC was
+** reported as "Fri Aug  7 05:25:18 2026" -- neither UTC, nor the system's local
+** time, nor the caller's.  See issue #145 for how the two offsets came to
+** disagree.
+**
+** And a local time is the wrong thing for an API to return at all.  The server
+** cannot know the caller's timezone, so any local rendering is unlabelled and
+** unusable -- the caller cannot tell which zone it is in.  Returning an
+** unambiguous instant and letting the client localize is what zowe and every
+** browser already do, and it is the convention mvsMF settled on elsewhere:
+** ussapi.c formats mtime with mgmtime64() and a literal "Z" (see
+** mvsmf docs/endpoints/uss/list.md).  Those timestamps never had this class of
+** bug precisely because they never touch localtime.
+**
+** So: gmtime64_r(), never ctime64() or localtime64().  That removes the
+** dependency on per-task timezone state rather than trying to keep two copies
+** of it in step.
+*/
+#include "jestime.h"
+#include "clib64.h"
+#include <stdio.h>
+
+void
+jestime(const time64_t *t, char *out, unsigned outlen)
+{
+    struct tm   tm;
+
+    if (!out || outlen == 0) return;
+    out[0] = 0;
+    if (!t) return;
+
+    /* a job that has not started (or has not ended) carries a zero time */
+    if (__64_cmp_u32((time64_t *)t, 0) == __64_EQUAL) {
+        snprintf(out, outlen, "...");
+        return;
+    }
+
+    if (!gmtime64_r(t, &tm)) {
+        snprintf(out, outlen, "...");
+        return;
+    }
+
+    /* ".000" rather than no fraction: this is the shape real z/OSMF emits for
+    ** exec-submitted / exec-started / exec-ended,
+    **     "exec-started":"2018-11-03T09:05:18.010Z"
+    ** and httpjes2 is the reference mvsMF's own implementation is compared
+    ** against, so the two should be directly comparable.  JES2 gives us second
+    ** resolution here (start_time64 is a time64_t), so the fraction is always
+    ** zero -- which is what z/OSMF itself reports for exec-submitted. */
+    snprintf(out, outlen, "%04d-%02d-%02dT%02d:%02d:%02d.000Z",
+             tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
+             tm.tm_hour, tm.tm_min, tm.tm_sec);
+}