啦啦啦……

punch.sh

#!/bin/bash

PUSH=false
DT=`date --rfc-3339=date`
MAX=36666

punch() {
    cur=-1
    while [  $((++cur)) -lt $MAX ]; do
        echo -e "\n$DT" >> punch.txt
        git add punch.txt
        git commit -m "$DT" --date="$DT"
        DT=`date -d "$DT +1 days" --rfc-3339=date`
    done
}

push() {
    $PUSH && git push
}

main() {
    punch
    push
}

usage() {
    echo -e "Usage:
  -d [yyyy-mm-dd] specify date
  -m [number]     max days, default 36666
  -p              push to remote"
}

# Main
while getopts 'd:m:ph' OPT; do
    case $OPT in
        d)
            DT=$(date -d "$OPTARG" --rfc-3339=date)
            [ $? -ne 0 ] && exit 1
            ;;
        m)
            MAX="$OPTARG"
            ;;
        p)
            PUSH=true
            ;;
        h)
            usage; exit 0
            ;;
        ?)
        usage
        exit 1
        ;;
    esac
done

shift $(($OPTIND - 1))

main