#!/bin/bash

#declare d="2016-05-06 00:00:00"
#d1=$(date -d "$d" +%s);
#echo $d1
#d2=$(date +%Y%m%d%H%M%S -d @$d1)
#echo $d2

#當前時間 年月日時分秒
#declare currentSecond=$(date +%Y%m%d%H%M%S)
#當前時間 年月日時分
#declare currentMinute=$(date +%Y%m%d%H%M)
#當前時間 年月日時
#declare currentHour=$(date +%Y%m%d%H)
#當前時間 年月日
#declare currentDay
 
=$(date +%Y%m%d)

declare currentHourOfSecond=$(date +%s)
declare currentHour=$(date +%Y%m%d%H -d @$currentHourOfSecond)
#[做運算時，運算符要和前後變量添加空格]
declare beforeOneHourOfSecond=`expr $currentHourOfSecond - 3600`
declare beforeOneHour=$(date +%Y%m%d%H -d @$beforeOneHourOfSecond)
declare beforeTwoHourOfSecond
 
=`expr $currentHourOfSecond - 7200`
declare beforeTwoHour=$(date +%Y%m%d%H -d @$beforeTwoHourOfSecond)
echo "beforeOneHour:"$beforeOneHour
echo "beforeTwoHour:"$beforeTwoHour

#獲取前一個小時時間
#declare beforeOneHour=$(date +%Y%m%d%H -d ‘-1 hours‘)
#獲取前兩個小時時間
#declare beforeTwoHour=$(date +%Y%m%d%H -d ‘-2 hours
 
‘)

#echo "currentSecond:"$currentSecond
#echo "currentMinute:"$currentMinute
#echo "currentHour:"$currentHour
#echo "currentDay:"$currentDay
#echo "beforeOneHour:"$beforeOneHour
#echo "beforeTwoHour:"$beforeTwoHour

shell日期格式和數字運算