diff --git a/sys/kern/kern_jail.c b/sys/kern/kern_jail.c
--- a/sys/kern/kern_jail.c
+++ b/sys/kern/kern_jail.c
@@ -223,6 +223,8 @@
 	{"allow.nfsd", "allow.nonfsd", PR_ALLOW_NFSD},
 #endif
 	{"allow.extattr", "allow.noextattr", PR_ALLOW_EXTATTR},
+	{"allow.adjtime", "allow.noadjtime", PR_ALLOW_ADJTIME},
+	{"allow.settime", "allow.nosettime", PR_ALLOW_SETTIME},
 };
 static unsigned pr_allow_all = PR_ALLOW_ALL_STATIC;
 const size_t pr_flag_allow_size = sizeof(pr_flag_allow);
@@ -4167,6 +4169,28 @@
 			return (0);
 		return (EPERM);
 
+		/*
+		 * Conditionally allow privileged process in the jail adjust
+		 * machine time.
+		 */
+	case PRIV_ADJTIME:
+	case PRIV_NTP_ADJTIME:
+		if (cred->cr_prison->pr_allow &
+		    (PR_ALLOW_ADJTIME | PR_ALLOW_SETTIME)) {
+			return (0);
+		}
+		return (EPERM);
+
+		/*
+		 * Conditionally allow privileged process in the jail set
+		 * machine time.
+		 */
+	case PRIV_CLOCK_SETTIME:
+		if (cred->cr_prison->pr_allow & PR_ALLOW_SETTIME)
+			return (0);
+		else
+			return (EPERM);
+
 	default:
 		/*
 		 * In all remaining cases, deny the privilege request.  This
@@ -4631,6 +4655,10 @@
 #endif
 SYSCTL_JAIL_PARAM(_allow, extattr, CTLTYPE_INT | CTLFLAG_RW,
     "B", "Jail may set system-level filesystem extended attributes");
+SYSCTL_JAIL_PARAM(_allow, adjtime, CTLTYPE_INT | CTLFLAG_RW,
+    "B", "Jail may adjust system time");
+SYSCTL_JAIL_PARAM(_allow, settime, CTLTYPE_INT | CTLFLAG_RW,
+    "B", "Jail may set system time");
 
 SYSCTL_JAIL_PARAM_SUBNODE(allow, mount, "Jail mount/unmount permission flags");
 SYSCTL_JAIL_PARAM(_allow_mount, , CTLTYPE_INT | CTLFLAG_RW,
diff --git a/sys/sys/jail.h b/sys/sys/jail.h
--- a/sys/sys/jail.h
+++ b/sys/sys/jail.h
@@ -254,7 +254,9 @@
 #define	PR_ALLOW_KMEM_ACCESS		0x00010000	/* reserved, not used yet */
 #define	PR_ALLOW_NFSD			0x00020000
 #define	PR_ALLOW_EXTATTR		0x00040000
-#define	PR_ALLOW_ALL_STATIC		0x000787ff
+#define	PR_ALLOW_ADJTIME		0x00080000
+#define	PR_ALLOW_SETTIME		0x00100000
+#define	PR_ALLOW_ALL_STATIC		0x001f87ff
 
 /*
  * PR_ALLOW_DIFFERENCES determines which flags are able to be
diff --git a/usr.sbin/jail/jail.8 b/usr.sbin/jail/jail.8
--- a/usr.sbin/jail/jail.8
+++ b/usr.sbin/jail/jail.8
@@ -656,6 +656,18 @@
 .It Va allow.extattr
 Allow privileged process in the jail to manipulate filesystem extended
 attributes in the system namespace.
+.It Va allow.adjtime
+Allow privileged process in the jail to slowly adjusting global operating system
+time.
+For example through utilities like
+.Xr ntpd 8 .
+.It Va allow.settime
+Allow privileged process in the jail to set global operating system data
+and time.
+For example through utilities like
+.Xr date 1 .
+This permission includes also
+.Va allow.adjtime .
 .El
 .El
 .Pp
@@ -1416,6 +1428,7 @@
 This is by virtue of the child jail being created in the chrooted
 environment of the first jail.
 .Sh SEE ALSO
+.Xr date 1 ,
 .Xr killall 1 ,
 .Xr lsvfs 1 ,
 .Xr newaliases 1 ,
@@ -1423,6 +1436,9 @@
 .Xr pkill 1 ,
 .Xr ps 1 ,
 .Xr quota 1 ,
+.Xr adjtime 2 ,
+.Xr clock_settime 2 ,
+.Xr ntp_adjtime 2 ,
 .Xr jail_set 2 ,
 .Xr devfs 4 ,
 .Xr fdescfs 4 ,
@@ -1444,6 +1460,7 @@
 .Xr mount 8 ,
 .Xr mountd 8 ,
 .Xr nfsd 8 ,
+.Xr ntpd 8 ,
 .Xr reboot 8 ,
 .Xr rpcbind 8 ,
 .Xr sendmail 8 ,