As Russ suggested in the 'patch/list sorry/proc-mtime' thread on 9fans here is a modified ps.
A -s flag prints process local start time.
Not sure about the -r option, maybe two extra options to ps is over kill?

Cheers,
John


Notes:
Mon Apr 10 12:31:19 EDT 2006 rsc
    Thanks.  I added the -r option because there is a nice
    formatting of it.  I don't see any nice formatting of -s
    so I left it out.  I don't like having formattings that
    completely change when passing certain thresholds.
    It makes them very hard to deal with programatically.
    


Reference: /n/sources/patch/applied/ps-start-run-time
Date: Wed Apr  5 16:43:45 CES 2006
Signed-off-by: j.krug@lancaster.ac.uk
Reviewed-by: rsc

--- /sys/src/cmd/ps.c	Wed Apr  5 16:38:59 2006
+++ /sys/src/cmd/ps.c	Thu Apr  6 15:11:10 2006
@@ -9,6 +9,8 @@
 Biobuf	bout;
 int	pflag;
 int	aflag;
+int	sflag;
+int	rflag;
 
 void
 main(int argc, char *argv[])
@@ -24,6 +26,12 @@
 	case 'p':
 		pflag++;
 		break;
+	case 'r':
+		rflag++;
+		break;
+	case 's':
+		sflag++;
+		break;
 	} ARGEND;
 	Binit(&bout, 1, OWRITE);
 	if(chdir("/proc")==-1)
@@ -54,9 +62,11 @@
 void
 ps(char *s)
 {
-	ulong utime, stime, size;
-	int argc, basepri, fd, i, n, pri;
-	char args[256], *argv[16], buf[64], pbuf[8], status[4096];
+	ulong utime, stime, size, runtime;
+	long tn=time(0);
+	int argc, basepri, fd, i, n, pri, days, hrs, mins, secs;
+	char args[256], *argv[16], buf[64], pbuf[8], sbuf[32], rbuf[32], status[4096];
+	Tm *pstm;
 
 	sprint(buf, "%s/status", s);
 	fd = open(buf, OREAD);
@@ -77,27 +87,54 @@
 	 * 1  user
 	 * 2  state
 	 * 3  cputime[6]
+	 * 5  runtime
 	 * 9  memory
 	 * 10 basepri
 	 * 11 pri
 	 */
 	utime = strtoul(argv[3], 0, 0)/1000;
 	stime = strtoul(argv[4], 0, 0)/1000;
+	runtime = strtoul(argv[5], 0, 0)/1000;
 	size  = strtoul(argv[9], 0, 0);
+
 	if(pflag){
 		basepri = strtoul(argv[10], 0, 0);
 		pri = strtoul(argv[11], 0, 0);
 		sprint(pbuf, " %2d %2d", basepri, pri);
 	} else
 		pbuf[0] = 0;
-	Bprint(&bout, "%-10s %8s %4lud:%.2lud %3lud:%.2lud%s %7ludK %-8.8s ",
-			argv[1],
-			s,
-			utime/60, utime%60,
-			stime/60, stime%60,
-			pbuf,
-			size,
-			argv[2]);
+
+	if(sflag){
+		pstm=localtime(tn-runtime);
+		if(runtime < 86400)
+			sprint(sbuf, " %02d:%02d:%02d",
+				pstm->hour, pstm->min, pstm->sec);
+		else
+			sprint(sbuf, " %d%02d%02d",
+				1900+pstm->year, 1+pstm->mon, pstm->mday);
+	} else
+		sbuf[0] = 0;
+
+	if(rflag){
+		secs = runtime%60;
+		mins = (runtime/60)%60;
+		hrs = (runtime/3600)%24;
+		days = runtime/86400;
+		sprint(rbuf, " %3d:%02d:%02d:%02d", 
+			days, hrs, mins, secs);
+	} else
+		rbuf[0] = 0;
+
+	Bprint(&bout, "%-10s %8s %4lud:%.2lud %3lud:%.2lud%s %7ludK%s%s %-8.8s ",
+		argv[1],
+		s,
+		utime/60, utime%60,
+		stime/60, stime%60,
+		pbuf,
+		size,
+		sbuf,
+		rbuf,
+		argv[2]);
 
 	if(aflag == 0){
     Noargs:
--- /sys/man/1/ps	Wed Apr  5 16:39:09 2006
+++ /sys/man/1/ps	Wed Apr  5 16:39:07 2006
@@ -4,12 +4,12 @@
 .SH SYNOPSIS
 .B ps
 [
-.B -pa
+.B -pasr
 ]
 .PP
 .B psu
 [
-.B -pa
+.B -pasr
 ]
 [
 .I user
@@ -93,6 +93,20 @@
 flag causes
 .I ps
 to print the arguments for the process.  Newlines in arguments will be translated to spaces for display.
+.PP
+With the
+.B -s
+flag,
+.I ps
+also prints, after the size, the local start time of each process. If less than 24 hours old the format is HH:MM:SS, if older the format is YYYYMMDD.
+.PP
+With the
+.B -r
+flag,
+.I ps
+also prints, after the size (or start time, if
+.B -s
+was given) the running time of each process as days, hours, minutes, and seconds.
 .SH FILES
 .B /proc/*/status
 .SH SOURCE