はじめまして、神谷と申します。
簡単なＳＱＬでテストしてみたのですが、
Timestampが勝ってに現在日時に変更するのですが、
これはバグでしょうか？

よろしくお願いします。

mysql> create table bug1 (id int(9) not null, calendar1 timestamp, flag 
int(1));
Query OK, 0 rows affected (0.01 sec)

mysql> select * from bug1;
+----+----------------+------+
| id | calendar1      | flag |
+----+----------------+------+
|  1 | 20000101000000 |    0 |
+----+----------------+------+
1 row in set (0.00 sec)

mysql> update bug1 set flag = 1;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> select * from bug1;
+----+----------------+------+
| id | calendar1      | flag |
+----+----------------+------+
|  1 | 20020709172403 |    1 |
+----+----------------+------+
1 row in set (0.00 sec)

mysql> status
--------------
./mysql  Ver 11.16 Distrib 3.23.49, for apple-darwin5.3 (powerpc)

Connection id:          8
Current database:       calendar
Current user:           test@localhost
Current pager:          stdout
Using outfile:          ''
Server version:         3.23.49
Protocol version:       10
Connection:             Localhost via UNIX socket
Client characterset:    sjis
Server characterset:    sjis
UNIX socket:            /tmp/mysql.sock
Uptime:                 35 min 46 sec

Threads: 1  Questions: 51  Slow queries: 0  Opens: 10  Flush tables: 1  
Open tables: 4 Queries per second avg: 0.024
--------------

************************************
Kazutaka KAMIYA
kzkamiya@xxxxxxxxxx
http://www.amtec.co.jp