#!/bin/bash

# Desc: Template to check that apps, files, or dirs exist.
# Author: Steven Baltaktei Sandoval
# License: GPLv3+

#==BEGIN Define script parameters==
#===BEGIN Declare local script functions===
timeUntilMidnight(){
    # Desc: Report seconds until midnight
    # Output: stdout: seconds until midnight
    TIME_CURRENT="$(date --iso-8601=seconds)" ; # Produce `date`-parsable current timestamp with resolution of 1 second.
    TIME_CURRENT_SHORT="$(date -d "$TIME_CURRENT" +%Y%m%dT%H%M%S%z)" # Produce separator-less current timestamp with resolution 1 second.
    DATE_CURRENT="$(date -d "$TIME_CURRENT" --iso-8601=date)" ; # Produce `date`-parsable current timestamp with resolution of 1 day.
    DATE_CURRENT_SHORT="$(date -d "$TIME_CURRENT" +%Y%m%d)" ; # Produce separator-less current timestamp with resolution 1 day.
    DATE_TOMORROW="$(date -d "$TIME_CURRENT next day" --iso-8601=date)" ; # Produce timestamp of tomorrow's date (res. 1 day).
    TIME_NEXT_MIDNIGHT="$(date -d "$DATE_TOMORROW" --iso-8601=seconds)" ; # Produce `date`-parsable timestamp of closest future midnight (res. 1 second).
    SECONDS_UNTIL_NEXT_MIDNIGHT="$(( $(date +%s -d "$TIME_NEXT_MIDNIGHT") - $(date +%s -d "$TIME_CURRENT") ))" ; # Calculate seconds until closest future midnight (res. 1 second).
    echo "$SECONDS_UNTIL_NEXT_MIDNIGHT" 2>/dev/null;
} # Report seconds until next midnight
#===END Declare local script functions===
#==END Define script parameters==


#==BEGIN sample code==
echo "Time until next midnight (seconds):$(timeUntilMidnight)"
#==END sample code==