Change from 10 minute interval time to 3 hour interval time.

10min_2_3hour.sh

#!/bin/sh
#
# program of converting from 10-min. time to 3-hour time
#
# original script coded by Takashi Unuma, Kyoto Univ.
# Last modified: 2013/05/22
#

if test ${#1} -lt 12 ; then
    echo "please type following format of date:"
    echo " YYYYMMDDHHNN"
    exit 1
fi

YMDHN=$1
yyyy=${YMDHN:0:4}
mm=${YMDHN:4:2}
dd=${YMDHN:6:2}
hh=${YMDHN:8:2}
nn=${YMDHN:10:2}

#echo "INPUT: ${hh}:${nn} ${mm}/${dd}/${yyyy}"
#echo "INPUT: ${yyyy}-${mm}-${dd}_${hh}:${nn}"

if test ${hh} -ge 0 -a ${hh} -le 1 ; then
    echo "${yyyy}${mm}${dd}0000"
elif test ${hh} -ge 2 -a ${hh} -le 4 ; then
    echo "${yyyy}${mm}${dd}0300"
elif test ${hh} -ge 5 -a ${hh} -le 7 ; then
    echo "${yyyy}${mm}${dd}0600"
elif test ${hh} -ge 8 -a ${hh} -le 10 ; then
    echo "${yyyy}${mm}${dd}0900"
elif test ${hh} -ge 11 -a ${hh} -le 13 ; then
    echo "${yyyy}${mm}${dd}1200"
elif test ${hh} -ge 14 -a ${hh} -le 16 ; then
    echo "${yyyy}${mm}${dd}1500"
elif test ${hh} -ge 17 -a ${hh} -le 19 ; then
    echo "${yyyy}${mm}${dd}1800"
elif test ${hh} -ge 20 -a ${hh} -le 22 ; then
    echo "${yyyy}${mm}${dd}2100"
elif test ${hh} -eq 23 ; then
    _dd=$(expr ${dd} + 1)
    if test ${mm} = "02" ; then
        if test $(expr ${yyyy} % 4) -eq 0 ; then
            if test ${_dd} -ge 30 ; then
                _mm=$(expr ${mm} + 1)
                _dd=1
            else
                _mm=$(expr ${mm} + 0)
                _dd=$(expr ${_dd} + 0)
            fi
        elif test ${_dd} -ge 29 ; then
            _mm=$(expr ${mm} + 1)
            _dd=1
        else
            _mm=$(expr ${mm} + 0)
            _dd=$(expr ${_dd} + 0)
        fi
        YYYY=${yyyy}
    elif test ${mm} = "01" -o ${mm} = "03" -o ${mm} = "05" -o ${mm} = "07" -o ${mm} = "08" -o ${mm} = "10" -o ${mm} = "12" ; then
        if test ${_dd} -ge 32 ; then
            YYYY=${yyyy}
            _mm=$(expr ${mm} + 1)
            _dd=1
        else
            YYYY=${yyyy}
            _mm=$(expr ${mm} + 0)
            _dd=$(expr ${_dd} + 0)
        fi
        if test ${_mm} -ge 13 ; then
            YYYY=$(expr ${yyyy} + 1)
            _mm=1
            _dd=1
        else
            YYYY=${yyyy}
        fi
    elif test ${mm} = "04" -o ${mm} = "06" -o ${mm} = "09" -o ${mm} = "11" ; then
        if test ${_dd} -ge 31 ; then
            _mm=$(expr ${mm} + 1)
            _dd=1
        else
            _mm=$(expr ${mm} + 0)
            _dd=$(expr ${_dd} + 0)
        fi
        YYYY=${yyyy}
    else
        echo "mm error"
    fi
    if test ${_mm} -lt 10 ; then
        MM="0${_mm}"
    else
        MM="${_mm}"
    fi
    if test ${_dd} -lt 10 ; then
        DD="0${_dd}"
    else
        DD="${_dd}"
    fi
    echo "${YYYY}${MM}${DD}0000"
else
    echo "hh error"
fi