diff --git a/Documentation/technical/api-trace2.txt b/Documentation/technical/api-trace2.txt
index baaa115..cdc00bc 100644
--- a/Documentation/technical/api-trace2.txt
+++ b/Documentation/technical/api-trace2.txt
@@ -78,11 +78,11 @@
 +
 ------------
 $ cat ~/log.event
-{"event":"version","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.620713","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
-{"event":"start","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621027","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
-{"event":"cmd_name","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621122","file":"git.c","line":432,"name":"version","hierarchy":"version"}
-{"event":"exit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621236","file":"git.c","line":662,"t_abs":0.001227,"code":0}
-{"event":"atexit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16 17:28:42.621268","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
+{"event":"version","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.620713Z","file":"common-main.c","line":38,"evt":"1","exe":"2.20.1.155.g426c96fcdb"}
+{"event":"start","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621027Z","file":"common-main.c","line":39,"t_abs":0.001173,"argv":["git","version"]}
+{"event":"cmd_name","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621122Z","file":"git.c","line":432,"name":"version","hierarchy":"version"}
+{"event":"exit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621236Z","file":"git.c","line":662,"t_abs":0.001227,"code":0}
+{"event":"atexit","sid":"1547659722619736-11614","thread":"main","time":"2019-01-16T17:28:42.621268Z","file":"trace2/tr2_tgt_event.c","line":163,"t_abs":0.001265,"code":0}
 ------------
 
 == Enabling a Target
@@ -542,7 +542,7 @@
 	"event":"version",
 	"sid":"1547659722619736-11614",
 	"thread":"main",
-	"time":"2019-01-16 17:28:42.620713",
+	"time":"2019-01-16T17:28:42.620713Z",
 	"file":"common-main.c",
 	"line":38,
 	...
diff --git a/trace2/tr2_tbuf.c b/trace2/tr2_tbuf.c
index 0844910..eb1b240 100644
--- a/trace2/tr2_tbuf.c
+++ b/trace2/tr2_tbuf.c
@@ -15,7 +15,7 @@
 		  tm.tm_min, tm.tm_sec, (long)tv.tv_usec);
 }
 
-void tr2_tbuf_utc_time(struct tr2_tbuf *tb)
+void tr2_tbuf_utc_datetime_extended(struct tr2_tbuf *tb)
 {
 	struct timeval tv;
 	struct tm tm;
@@ -26,7 +26,7 @@
 	gmtime_r(&secs, &tm);
 
 	xsnprintf(tb->buf, sizeof(tb->buf),
-		  "%4d-%02d-%02d %02d:%02d:%02d.%06ld", tm.tm_year + 1900,
+		  "%4d-%02d-%02dT%02d:%02d:%02d.%06ldZ", tm.tm_year + 1900,
 		  tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec,
 		  (long)tv.tv_usec);
 }
diff --git a/trace2/tr2_tbuf.h b/trace2/tr2_tbuf.h
index 9cdefa3..2a1d173 100644
--- a/trace2/tr2_tbuf.h
+++ b/trace2/tr2_tbuf.h
@@ -16,8 +16,8 @@
 void tr2_tbuf_local_time(struct tr2_tbuf *tb);
 
 /*
- * Fill buffer with formatted UTC time string.
+ * Fill buffer with formatted UTC datatime string.
  */
-void tr2_tbuf_utc_time(struct tr2_tbuf *tb);
+void tr2_tbuf_utc_datetime_extended(struct tr2_tbuf *tb);
 
 #endif /* TR2_TBUF_H */
diff --git a/trace2/tr2_tgt_event.c b/trace2/tr2_tgt_event.c
index 48d9193..2c97cf5 100644
--- a/trace2/tr2_tgt_event.c
+++ b/trace2/tr2_tgt_event.c
@@ -94,7 +94,7 @@
 	 */
 	if (!tr2env_event_be_brief || !strcmp(event_name, "version") ||
 	    !strcmp(event_name, "atexit")) {
-		tr2_tbuf_utc_time(&tb_now);
+		tr2_tbuf_utc_datetime_extended(&tb_now);
 		jw_object_string(jw, "time", tb_now.buf);
 	}