diff --git a/usr.bin/leave/leave.c b/usr.bin/leave/leave.c
index c83eb02a0b8e..d4db4349d4de 100644
--- a/usr.bin/leave/leave.c
+++ b/usr.bin/leave/leave.c
@@ -1,180 +1,180 @@
 /*
  * SPDX-License-Identifier: BSD-3-Clause
  *
  * Copyright (c) 1980, 1988, 1993
  *	The Regents of the University of California.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  * 3. Neither the name of the University nor the names of its contributors
  *    may be used to endorse or promote products derived from this software
  *    without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
 
-#include <err.h>
 #include <ctype.h>
+#include <err.h>
 #include <locale.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <time.h>
 #include <unistd.h>
 
 static void doalarm(u_int);
 static void usage(void) __dead2;
 
 /*
  * leave [[+]hhmm]
  *
  * Reminds you when you have to leave.
  * Leave prompts for input and goes away if you hit return.
  * It nags you like a mother hen.
  */
 int
 main(int argc, char **argv)
 {
 	u_int secs;
 	int hours, minutes;
 	char c, *cp = NULL;
 	struct tm *t;
 	time_t now;
 	int plusnow, t_12_hour;
 	char buf[50];
 
 	if (setlocale(LC_TIME, "") == NULL)
 		warn("setlocale");
 
 	if (argc < 2) {
 #define	MSG1	"When do you have to leave? "
 		(void)write(STDOUT_FILENO, MSG1, sizeof(MSG1) - 1);
 		cp = fgets(buf, sizeof(buf), stdin);
 		if (cp == NULL || *cp == '\n')
-			exit(0);
+			exit(EXIT_SUCCESS);
 	} else if (argc > 2)
 		usage();
 	else
 		cp = argv[1];
 
 	if (*cp == '+') {
 		plusnow = 1;
 		++cp;
 	} else
 		plusnow = 0;
 
 	for (hours = 0; (c = *cp) && c != '\n'; ++cp) {
 		if (!isdigit(c))
 			usage();
 		hours = hours * 10 + (c - '0');
 	}
 	minutes = hours % 100;
 	hours /= 100;
 
 	if (minutes < 0 || minutes > 59)
 		usage();
 	if (plusnow)
 		secs = hours * 60 * 60 + minutes * 60;
 	else {
 		(void)time(&now);
 		t = localtime(&now);
 
 		if (hours > 23)
 			usage();
 
 		/* Convert tol to 12 hr time (0:00...11:59) */
 		if (hours > 11)
 			hours -= 12;
 
 		/* Convert tm to 12 hr time (0:00...11:59) */
 		if (t->tm_hour > 11)
 			t_12_hour = t->tm_hour - 12;
 		else
 			t_12_hour = t->tm_hour;
 
 		if (hours < t_12_hour ||
 	 	   (hours == t_12_hour && minutes <= t->tm_min))
 			/* Leave time is in the past so we add 12 hrs */
 			hours += 12;
 
 		secs = (hours - t_12_hour) * 60 * 60;
 		secs += (minutes - t->tm_min) * 60;
 		secs -= now % 60;	/* truncate (now + secs) to min */
 	}
 	doalarm(secs);
-	exit(0);
+	exit(EXIT_SUCCESS);
 }
 
 void
 doalarm(u_int secs)
 {
 	int bother;
 	time_t daytime;
 	char tb[80];
 	int pid;
 
 	if ((pid = fork())) {
 		(void)time(&daytime);
 		daytime += secs;
 		strftime(tb, sizeof(tb), "%+", localtime(&daytime));
 		printf("Alarm set for %s. (pid %d)\n", tb, pid);
-		exit(0);
+		exit(EXIT_SUCCESS);
 	}
 	sleep((u_int)2);		/* let parent print set message */
 	if (secs >= 2)
 		secs -= 2;
 
 	/*
 	 * if write fails, we've lost the terminal through someone else
 	 * causing a vhangup by logging in.
 	 */
 #define	FIVEMIN	(5 * 60)
 #define	MSG2	"\07\07You have to leave in 5 minutes.\n"
 	if (secs >= FIVEMIN) {
 		sleep(secs - FIVEMIN);
 		if (write(STDOUT_FILENO, MSG2, sizeof(MSG2) - 1) != sizeof(MSG2) - 1)
-			exit(0);
+			exit(EXIT_SUCCESS);
 		secs = FIVEMIN;
 	}
 
 #define	ONEMIN	(60)
 #define	MSG3	"\07\07Just one more minute!\n"
 	if (secs >= ONEMIN) {
 		sleep(secs - ONEMIN);
 		if (write(STDOUT_FILENO, MSG3, sizeof(MSG3) - 1) != sizeof(MSG3) - 1)
-			exit(0);
+			exit(EXIT_SUCCESS);
 	}
 
 #define	MSG4	"\07\07Time to leave!\n"
 	for (bother = 10; bother--;) {
 		sleep((u_int)ONEMIN);
 		if (write(STDOUT_FILENO, MSG4, sizeof(MSG4) - 1) != sizeof(MSG4) - 1)
-			exit(0);
+			exit(EXIT_SUCCESS);
 	}
 
 #define	MSG5	"\07\07That was the last time I'll tell you.  Bye.\n"
 	(void)write(STDOUT_FILENO, MSG5, sizeof(MSG5) - 1);
-	exit(0);
+	exit(EXIT_SUCCESS);
 }
 
 static void
 usage(void)
 {
 	fprintf(stderr, "usage: leave [[+]hhmm]\n");
-	exit(1);
+	exit(EXIT_FAILURE);
 }