Creating 28 checkboxes with a common name and different values
It seems to me that what you really need to do is change the view code. For example, if you do this:

&lt;input type="checkbox" name="Timeschedule" id="checkbox1" value="OneTime"&gt;
&lt;input type="checkbox" name="Timeschedule" id="checkbox2" value="Weekly"&gt;


That will automatically bind to the Timeschedule property on your SubscriptionPlanCreateViewModel. However, if the user selects multiple checkboxes, the values will probably come across as comma-separated. You can either make Timeschedule an array (which would probably better represent what you're doing from a data perspective) or you can simply replace the commas with " | " to produce the string you say you want in your comments.