## 対象バージョン

- ruby 2.1.2

- Rails 4.2.1

## 現在日時の取得

```
now = Time.current
```

## N日前・N日後

```
now = Time.current
# 昨日
now.yesterday
# 翌日
now.tomorrow
# N日前,N日後
now.ago(3.days)
now.since(3.days)
```

## Nヶ月前・Nヶ月後

```
now = Time.current
# 前月
now.prev_month
# 翌月
now.next_month
# Nヶ月前,Nヶ月後
now.ago(3.month)
now.since(3.month)
```

## N年前・N年後

```
now = Time.current
# 前年
now.prev_year
# 翌年
now.next_year
# N年前,N年後
now.ago(3.years)
now.since(3.years)
```

## その他

```
now = Time.current
# 月初
now.beginning_of_month
# 月末
now.end_of_month
# 今週の最初
now.beginning_of_week
# 今週の末
now.end_of_week
# 先週の月曜日
now.prev_week(:monday)
# 翌週の月曜日
now.next_week(:monday)
```