handling date in linux bash

linux-date-handling.sh

# I want compress yesterday's log, so I have to learn how to get yesterday with bash
# yesterday=$(date --date='-1 day' +%Y-%m-%d)
# today=$(date +%Y-%m-%d)
# yesterday_log=service_log_${yesterday}.log
# zip ${yesterday_log}.zip ${yesterday_log}

## today
today=$(date +%Y-%m-%d)

## Yesterday
yesterday_one=$(date --date='1 day ago' +%Y-%m-%d)
yesterday_two=$(date --date='-1 days' +%Y-%m-%d)

echo $yesterday_one
echo $yesterday_two

## tomorrow
tomorrow_one=$(date --date='1 day' +%Y-%m-%d)
tomorrow_two=$(date --date='+1 days' +%Y-%m-%d)

echo $tomorrow_one
echo $tomorrow_two


## other (second/minute/hour/week/month/year)
## more exmaples
date -d "-1 month"
date -d "-1 months"
date -d "+1 month"
date -d "+1 months"
date -d "-1 year"
date -d "-1 years"
date -d "+1 year"
date -d "+1 years"