#!/usr/bin/env bash

MINUTE=60
HOUR=$(($MINUTE * 60))
DAY=$(($HOUR * 24))
MONTH=$(($DAY  * 30))
YEAR=$(($DAY * 365))

if [[ $# < 2 ]]; then
    echo "Usage: $0 <birthdate> <age>"
    exit
fi

print_lifetime() {
    future=$(date +%s -d "$1 + $2 years")
    epoch=$(($future - $(date +%s)))

    echo "Seconds until $2 years old: $epoch"
    echo "Minutes until $2 years old: $(($epoch / $MINUTE))"
    echo "Hours until $2 years old: $(($epoch / $HOUR))"
    echo "Days until $2 years old: $(($epoch / $DAY))"
    echo "Months until $2 years old: $(($epoch / $MONTH))"
    echo "Years until $2 years old: $(($epoch / $YEAR))"
}


print_lifetime "$1" "$2"