Admin page repeatable fields

Try this one http://jsfiddle.net/jaredwilli/tZPg4/4/

and use array so input should be something like this

<input type="text" name="data[1][time][start]">
<input type="text" name="data[1][time][end]">

<input type="text" name="data[2][time][start]">
<input type="text" name="data[2][time][end]">

….

then save data as array

update_post_meta($post_id, 'field_name', $_POST['data']);