mysql> SELECT CURDATE();
+------------+
| CURDATE()  |
+------------+
| 2006-08-10 |
+------------+
1 row in set (0.01 sec)

mysql> SELECT NOW();
+---------------------+
| NOW()               |
+---------------------+
| 2006-08-10 15:41:19 |
+---------------------+
1 row in set (0.01 sec)

mysql> SELECT UNIX_TIMESTAMP();
+------------------+
| UNIX_TIMESTAMP() |
+------------------+
|       1155238891 |
+------------------+
1 row in set (0.00 sec)