How to count / sum with criteria DATE & TIME ?

I use this sheet for count my product's selling
I want predict which date & time when buyer come to my shoes to buy my product (example i open from 08:00 AM - 16:00 PM and many of buyer always buy from 9 AM until 9:30 AM)
So if i type date, time & No. Invoice then No. Buyer increase 1 by 1. Its for calculate how many people buy from my shop.
I just want to know how many buyer in each day and know which time buyer always buy.


I attach sheet that i want.
As from that sheet mean : at 18 Feb, i have 3 buyer & 19 Feb, i have 2 buyer

Sorry if someone try to give solution by using VB Makro, i don't know how to open because i'm open this sheet from mobile.

Hi coba66, welcome to the forum. The attached workbook uses a multi-cell Array Formula to calculate half-hourly purchase frequencies.
To enter such a formula, select the cells that will share it (C2:S2 in the example), click in the formula bar, paste the formula, and press CTRL+SHIFT+ENTER (all at once). Braces {} will surround the formula text, signifying successful array entry. Then copy the formula row down.

Please Login or Register  to view this content.

I also used a formula in a helper column on the data sheet to provide consistent dates and times for the main formula. Sheet1!F2 and copied down:

Please Login or Register  to view this content.

*Always press CTRL+SHIFT+ENTER to confirm entry after pasting or editing an ARRAY FORMULA in the Formula Bar.
When copying the formula to other cells, make sure the copied cell is not part of the Paste Area.

Originally Posted by coba66

...Maybe i can use IF for check if number invoice didn't fill it then it can't counting to be buyer.

Yes, that will work. In fact, if every invoice has a time, you can just check for the invoice. Try this in Sheet1!F2, copied down:

Please Login or Register  to view this content.