Script to set date/time of macbook without a battery

README.md

Copy the launch daemon file named com.startup.script.plist in /Library/LaunchDaemons. Then set the permissions for it

sudo chmod +x /Library/LaunchDaemons/com.startup.script.plist
sudo chown root:wheel /Library/LaunchDaemons/com.startup.script.plist

Next copy the shell script updatetime.sh in /usr/local/bin/. Make it executable with sudo chmod +x /usr/local/bin/updatetime.sh and owned by root:wheel with sudo chown root:wheel /usr/local/bin/updatetime.sh.

Enable and launch the Daemon with:

sudo launchctl load -w /Library/LaunchDaemons/com.startup.script.plist

com.startup.script.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>Label</key>
    <string>com.startup.script</string>
    <key>LaunchOnlyOnce</key>
    <true/>
    <key>ProgramArguments</key>
    <array>
        <string>sh</string>
        <string>-c</string>
        <string>/usr/local/bin/updatetime.sh</string>
    </array>
    <key>RunAtLoad</key>
    <true/>
</dict>
</plist>

updatetime.sh

#!/bin/bash
# Insane bash script that sets date and time of macbook via ntpdate when the battery has been removed.
# Don't try to use `ntpd -q` instead of `ntpdate <server>` it's fuuuuucked.
FILE=lastdate.txt
LOCK=shutdown.lock


function ifup {
	((count = 100))                            # Maximum number to try.
	while [[ $count -ne 0 ]] ; do
		ping -c 1 8.8.8.8                      # Try once.
		rc=$?
		if [[ $rc -eq 0 ]] ; then
			((count = 1))                      # If okay, flag to exit loop.
		fi
		((count = count - 1))                  # So we don't go forever.
	done

	if [[ $rc -eq 0 ]] ; then                  # Make final determination.
		echo "The internet is back up. Setting date and time."
		ntpdate time.euro.apple.com
	
	else
		echo "Internet connection unavailable. Time may be incorrect."
		osascript -e 'display notification "Please connect to internet and restart to update time." with title "Time updater"'
	fi
}

function writedate {
	datevars="lastdate=$(date +%m%d%H%M%Y)";
	echo "$datevars" > "$FILE"
	touch $LOCK

}

function filedate {
	if test -f "$FILE"; then
		echo "Date data $FILE exists."
		source $FILE
		date "$lastdate"
		ifup
		writedate
	else
		echo "Date data $FILE not found. Setting January 2021 and forcing network time update."
		date 012210062021
		ifup
		writedate
	fi
}

function update {
	if test -f "$LOCK"; then
		echo "Lock file exists"
		ifup
		writedate
		echo "Updated time to last known time"
	else
		filedate
	fi
}

function shutdown {
	echo "$datevars"
	rm $LOCK
	writedate
}

trap shutdown SIGTERM
trap shutdown SIGKILL

if [ -f "$LOCK" ] ; then
	osascript -e 'display notification "Last shutdown was abrupt, time may be wrong!" with title "Time updater"'
fi

osascript -e 'display notification "Please make sure internet is connected, else time may be wrong." with title "Time updater"'

while true; do update & sleep 60; done