Field does not clear

I have a question in regard to my app at www.Parlin.com  [JotForm: Volunteers Report Sheet]

I the field of [Dates You Worked] it save the date from the prior month.
I would like to have the entry field clear for each new month. Is there a way to do that?

Perhaps there is some other field I could use instead. Can you help?

I cloned your form and tested it but i didn't create the scenario you mentioned  above. When i filled those fields, i could enter any number or letter and there is no warning or conditions on your form for that. In order to clear some points, do you mean that when your  enduser enters "Todays Date", "Dates You Worked" field is calculated automatically starting from the one month before for each month?

If not, could you please give us some more details to assist you in a better way. 

Waiting for your return.