Index: tests/sys/netpfil/pf/Makefile
===================================================================
--- tests/sys/netpfil/pf/Makefile
+++ tests/sys/netpfil/pf/Makefile
@@ -18,6 +18,7 @@
 		pfsync	\
 		rdr \
 		route_to \
+		schedule \
 		set_skip \
 		set_tos \
 		src_track \
Index: tests/sys/netpfil/pf/schedule.sh
===================================================================
--- /dev/null
+++ tests/sys/netpfil/pf/schedule.sh
@@ -0,0 +1,97 @@
+# $FreeBSD$
+#
+# SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+#
+# Copyright (c) 2021 Rubicon Communications, LLC (Netgate)
+#
+# 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.
+#
+# THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+
+. $(atf_get_srcdir)/utils.subr
+
+common_dir=$(atf_get_srcdir)/../common
+
+atf_test_case "basic" "cleanup"
+basic_head()
+{
+	atf_set descr 'Test basic functionality of schedule keyword'
+	atf_set require.user root
+}
+
+basic_body()
+{
+	pft_init
+
+	epair=$(vnet_mkepair)
+	ifconfig ${epair}a 192.0.2.1/24 up
+
+	vnet_mkjail alcatraz ${epair}b
+	jexec alcatraz ifconfig ${epair}b 192.0.2.2/24 up
+	jexec alcatraz pfctl -e
+
+	pft_set_rules alcatraz "block all" \
+		"pass in proto icmp schedule testsched"
+
+	# Sanity check & establish state
+	# Note: use pft_ping so we always use the same ID, so pf considers all
+	# echo requests part of the same flow.
+	atf_check -s exit:0 -o ignore ${common_dir}/pft_ping.py \
+		--sendif ${epair}a \
+		--to 192.0.2.2 \
+		--replyif ${epair}a
+
+	# Change rules to now deny the ICMP traffic
+	pft_set_rules noflush alcatraz "block all"
+
+	# Established state means we can still ping alcatraz
+	atf_check -s exit:0 -o ignore ${common_dir}/pft_ping.py \
+		--sendif ${epair}a \
+		--to 192.0.2.2 \
+		--replyif ${epair}a
+
+	# Kill states with a different schedule
+	jexec alcatraz pfctl -y othersched
+
+	# So we can still ping
+	atf_check -s exit:0 -o ignore ${common_dir}/pft_ping.py \
+		--sendif ${epair}a \
+		--to 192.0.2.2 \
+		--replyif ${epair}a
+
+	# Kill established state
+	jexec alcatraz pfctl -y testsched
+
+	# Now the ping fails
+	atf_check -s exit:1 -o ignore ${common_dir}/pft_ping.py \
+		--sendif ${epair}a \
+		--to 192.0.2.2 \
+		--replyif ${epair}a
+}
+
+basic_cleanup()
+{
+	pft_cleanup
+}
+
+atf_init_test_cases()
+{
+	atf_add_test_case "basic"
+}