What did you try? Why don't you read the documentation? Do you think your computer or we here should be able to read your mind?

here is my testrun, everything works as it should - don't just make something up in your head and falter surrender if that failes, read the documentation carefully, experiment with the stuff you read and think:

mysql> create table tstest( ts timestamp not null default now());
Query OK, 0 rows affected (0.03 sec)

mysql> insert into tstest values(from_unixtime(114454234));
Query OK, 1 row affected (0.00 sec)

mysql> select * from tstest;
+---------------------+
| ts                  |
+---------------------+
| 1973-08-17 17:50:34 |
+---------------------+
1 row in set (0.00 sec)
[download]

Edit: altered a word to get nearer to the intended meaning...(marked via strike out)