Ok, maybe the easiest trick would to make the value appear as date (in the Y-m-d H:i:s format) and keep it in epoch value inside your datebase.
What i mean is something like: your template (default.php) gets the DB value (in epoche) and for a millisecond shows it as epoche. You then change that via jQuery.
Ok, let's try the most hardest thing: to get you into the programming fun
Please consider this not beeing the most beautiful and recommende way, but it will show you quickly what i want to teach you...
1. Go to your own template folder.
2. open the index.php
3. before the </body> tag appears put in this code:
HTML:
<script>
alert("Here i am");
</script>
If you check your page now, there should be a javascript pop up saying "Here i am".
If this works - fiiiine
4. Now remove the alert line.
5. insert this code between the SCRIPT tags you just wrote
HTML:
myDate = new Date(1000*1344988800);
theNewTime = myDate.toString()
alert(theNewTime);
What we have now is that a alert showing "theNewTime".
6. now e will exchange the "fixed" time value (1344988800) in the code above with the value of your list / table field.
To get the value of your field you can use the jquery syntax like this
$( "div.demo-container" ).text() or $( "div.demo-container" ).val()
So the code could look something like this:
HTML:
<script>
// this gets the value inside the DIV with the ID "fabrikInput_row___purchase_date" and inserts it into a new variable.
thetimeVal = $("#fabrikInput_row___purchase_date").val();
myDate = new Date(1000*thetimeVal);
theNewTime = myDate.toString()
// this line takes the DIV with the ID farikInput_row___purchase_date and exchanges the text inside it.
$("#fabrikInput_row___purchase_date").val(theNewTime);
</script>
Please be aware this is very raw mode and i have not tested it out. I just want to show you some kind of path how i would archive it.
Good luck my friend!