select current_date;
select date 'today';
select timestamp 'today';
// select current_date + '-1 days'; // エラーになる
select current_date - 1;
select date 'yesterday';
select timestamp 'yesterday'; // 時間は00:00:00
select now() + '-1 days';
select current_date + 1;
select date 'tomorrow';
select timestamp 'tomorrow';
select now() + '1 days';
select current_date - 7;
select current_timestamp - 7;
select current_timestamp + '-7 days';