How to trigger reload when time updated in procd init script?

how to trigger reload when time is updated in procd init script ?

i have created /etc/init.d/openvfd like this :

#!/bin/sh /etc/rc.common
# Copyright (C) 2016-2017 Hsing-wang Liao <kuoruan@gmail.com>
# Licensed to the public under the Apache License 2.0.

START=99
USE_PROCD=1

NAME=openvfd
PROG=/sbin/vfdservice

start_service() {
	procd_open_instance "$NAME"
	procd_set_param command /sbin/vfdservice # service executable that has to run in **foreground**.
	procd_set_param stdout 1 # forward stdout of the command to logd
	procd_set_param stderr 1 # same for stderr
	procd_set_param user root # run service as user root
	procd_set_param pidfile /var/run/openvfd.pid # write a pid file on instance start and remove it on stop
	procd_set_param term_timeout 60 # wait before sending SIGKILL
	procd_close_instance
}

i want to do reload when time is changed, i have read https://openwrt.org/docs/guide-developer/procd-init-scripts which contains :

procd_set_param file /var/etc/your_service.conf # /etc/init.d/your_service reload will restart the daemon when these files have changed
procd_set_param netdev dev # likewise, but for when dev's ifindex changes.
procd_set_param data name=value ... # likewise, but for when this data changes.

but i dont know what value i can use to either procd_set_param file or procd_set_param data ?