Can I limit an entry to 1x per day

using jotform for a giveaway entry .  want to limit entries to 1x day

people can enter 1x/day for the duration of the promotion (1 month)

If you wish to limit the submission in your form to just 1 per day, you can follow the instructions in this guide — How-to-set-Form-Limits-Based-on-a-Unique-Question

You will set a Date Picker field as the unique question and that Date Picker field is set to have the "Current Date"

and is also hidden on the form — How-to-Hide-Form-Fields

However, if you want to limit the submission of every respondent to just 1 per day, please follow the instructions in this guide instead — How-to-Have-Unique-Question-Using-Multiple-Fields

Then, instead of just having a Date Picker field to check the submissions uniqueness, you can include the Name field where your respondents will enter their name.

Please give it a try and let us know if you need any further assistance.