dotfiles/.config/shell/functions/sleep-until

#!/bin/sh
# Usage: sleep_until <time>
# Ex: sleep_until 3:00 pm

sleep_until() {
   if [ -n "$1" ] && date --date="$*" > /dev/null 2>&1; then
      SLEEP_TIME="$(( $(date -f - +%s- <<< "$*"$'\nnow') 0 ))"
      if [ "$SLEEP_TIME" -gt 0 ]; then
         echo "Sleeping until:  $(date --date="$*")  (${SLEEP_TIME}s)"
         sleep "$SLEEP_TIME"
      else
         echo "Sadly, you cannot sleep to a time in the past"
      fi
   else
      echo "Please input a date"
   fi
}