Record grandfather clock strikes every hour on Linux

RecordStrikes.bash

#!/bin/bash
# Record grandfather clock strikes every hour
# Narjala Bhasker
# 6/13/2019

TARGET_TIME_SECS=$((59*60))

while true 
do
	# Sleep until 59 minutes past the hour
	CURRENT_TIME_SECS=$(($(date +%-M) * 60 + $(date +%-S)))

	SLEEP_TIME_SECS=$(($TARGET_TIME_SECS - $CURRENT_TIME_SECS))
	
	if [[ $SLEEP_TIME_SECS -le 0 ]]
	then
		SLEEP_TIME_SECS=$((SLEEP_TIME_SECS + 3600))
	fi
	
	
	echo "Target Time:  " $TARGET_TIME_SECS
	echo "Current Time: " $CURRENT_TIME_SECS
	echo "Sleep Time:   " $SLEEP_TIME_SECS
	
	sleep $SLEEP_TIME_SECS
	
	FILE_NAME=$(date "+%Y.%m.%d-%H.%M.%S")".wav"
	
	# Record 120 seconds of audio and save into appropriately named file	
	arecord -f CD -d 120 $FILE_NAME	
	echo $FILE_NAME " written"
done