what should i write at the criteria of the date

DateSerial

What have you tried?

What do you think you need to do?
Write it out in pseudo code first for us.

i really don't know what functions i will use, Dear Alex
i am a person who knows access in the last seveal months, even i purchased lessons, i couldn't use it well, just know what i want to get. 0.0

You may need to watch the videos more than one time.  Richard gives you the method to do the Last 30 days in Expert 11 Lesson 07.

If you want to know the last week (Hint: a week is 7 days) you would just adjust that formula accordingly.

I really hope you are not just watching the videos but you are following Richard's advice on truly KNOWING Access.  
1. Watch the video the first time all the way through - don't do any work.
2. The second time watch the video and do the database he is making as he is making it. Pause the video as needed and back up if necessary.  This method of doing while you are watching will help to glue the knowledge in your brain better than just watching the videos and expecting to remember it in the future.

Alexis, we're here to help you LEARN Access, but not to just do the work for you. Watch the lessons. Do the examples. Figure it out. If you get stuck, post your questions, but we're not all about just giving you the answers. We want you to learn the material for yourself.

thanks for everyone reply

well, i do my access database indeed by myself after learning. friend. i want to learn the access knowlege to use in my work, if it doesn't useful i don't spend my money and my time to learn it, just like everyone leaning the access reason, that's also some reasons like you, Dear Mr. Richard

the question i ask is for my database, but it's more complex to explain my data, so i use the your lesson material to ask. i don't know why all of you think i am lazy, not think by myself, not do the test. maybe the way of asking is wrong, next time i will have a thinking before i ask.

anyway, thanks everyone. i really indeed listening again and again, and try to add more access functions by myself, but for now, it's more difficult, hope all of you undestand

by the way, thank you for Mr. Scott. thank you for your answers and advise. i am always learning like what you said. leaning and do it by myself for the material, and use it in my database

and Dear Richard. thank you for your email yesterday, anyway, thank you for your kindly reply, for my pocket i think i will purchase half of your developer lessons, and then pay the rest of half lessons next month

Your lessons are a little difficult for me, you know english is not my mother language, otherwise, the access function is really really complex but usefull, i think i will get the knowlege well, it will be one year later, hope you can understand my situation, haha

Alexis, nobody said you were being lazy. I'm just trying to let you understand that we're here to help you LEARN Access, and not just give you the answers to every question you have. You will learn better if we point you in the right direction and let you figure some things out on your own, from the lessons.

yes, thank you, Dear Richard. thank you for everyone. i will do that like what you said, i was doing that, and i will keep on doing that. Teacher