Calculate extra hours with bash script

Here is a bash script which is able to calculate time worked. It takes some arguments (as departure time, arrival time etc..) and gives you back the time spent.

Code

#! /bin/bash

#Functions
FunctionGetTime()
{
	read -e -p "Arrival time (h:mm) :" -i "8:00" r_HOUR_ARR #get arrival time, 8:00 will be proposed by default
	read -e -p "Lunch break (h:mm) :" -i "0:00" r_BREAK_LUN #get lunch break, 0:00 will be proposed by default
	read -e -p "Departure time (h:mm) :" -i "17:00" r_HOUR_DEP #get departure time, 17:00 will be proposed by default
	if [ "$1" = false ]; then
		read -e -p "Arrival time (to home) (h:mm) :" -i "17:00" r_HOUR_ARR_DOM #get arrival at home, 17:00 will be proposed by default
	fi
}

read -e -p "Departure time (from home) (h:mm) :" -i "0:00" r_HOUR_DEP_DOM #get departure time, 0:00 will be proposed by default

if [ "$r_HOUR_DEP_DOM" == "0:00" ]; then #we don't calculate total time if Departure time is equal to 0:00
	echo "We only calculate the intervention time and any overtime."
	FunctionGetTime true
else
	FunctionGetTime false
fi

#We convert every hour to the universal format (-u to avoid hours differences if executed from another time zone) compared to the time of ref 01/01/1970
HOUR_SOURCE=$(date -u -d "1970-01-01" +%s)
HOUR_DEP_DOM=$(date -u -d "1970-01-01 $r_HOUR_DEP_DOM" +%s)
HOUR_ARR=$(date -u -d "1970-01-01 $r_HOUR_ARR" +%s)
BREAK_LUN=$(date -u -d "1970-01-01 $r_BREAK_LUN" +%s)
HOUR_DEP=$(date -u -d "1970-01-01 $r_HOUR_DEP" +%s)
HOUR_ARR_DOM=$(date -u -d "1970-01-01 $r_HOUR_ARR_DOM" +%s)

dej_diff=$(( (BREAK_LUN - HOUR_SOURCE) ))
duration_diff=$(( (HOUR_DEP - HOUR_ARR - dej_diff) ))
duration_dest=$(date -u -d"@$duration_diff" "+%H:%M")

IN=$(echo "$duration_dest" | awk -F: '{ print ($1 * 60) + $2 }')

#Extra hours calculation
HOUR_SUPP=$(date -u -d "1970-01-01 7:00" +%s)
HOUR_SUPP=$(( (HOUR_SUPP - HOUR_SOURCE) )) #we put 25200 in HOUR_SUPP which is our 7 hours work
duration_diff_sup=$(( (HOUR_ARR_DOM - HOUR_DEP_DOM - dej_diff) ))

if [ "$duration_diff_sup" -gt "$HOUR_SUPP" ]; then #25200 which is our 7 hours work 
	supp_diff=$(( (duration_diff_sup - HOUR_SUPP) ))
	supp_time=$(date -u -d"@$supp_diff" "+%R") #%R is another way to write %H:%M
	echo -e "\nCall out time is : $duration_dest ($MIN minutes). There is $supp_time extra hours."
	exit 0
elif [ "$duration_diff" -gt "$HOUR_SUPP" ]; then 
	supp_diff=$(( (duration_diff - HOUR_SUPP) ))
	supp_time=$(date -u -d"@$supp_diff" "+%R") #%R is another way to write %H:%M
	echo -e "\nCall out time is : $duration_dest ($MIN minutes). There is $supp_time extra hours."
	exit 0
else
	echo -e "\nCall out time is : $duration_dest ($MIN minutes). There is no extra hours."
fi

• Download : extrahours.sh