DATE '2015-03-12' + 1 DAY;
TIMESTAMP '2015-03-12' + 1 DAY;
TIMESTAMP '2015-03-12 10:10:10.000' + 1 MICROSECOND;

DATE '2015-03-12' + NVL(NULL, 3) DAYS;
TIMESTAMP '2015-03-12' + NVL(NULL, 3) DAYS;

DATE '2015-03-12' - 1 DAY;
TIMESTAMP '2015-03-12' - 1 DAY;
TIMESTAMP '2015-03-12 10:10:10.000' - 1 MICROSECOND;

DATE '2015-03-12' - NVL(NULL, 3) DAYS;
TIMESTAMP '2015-03-12' - NVL(NULL, 3) DAYS;

TIMESTAMP '2015-03-12' - 1 DAY - 1 MICROSECOND;

date '2016-01-27' - interval '3' day;