help needed, date and times to and from and running total help

[zebturner]

Hi, my friend has a hotel and wants me to devise a spreadsheet, I have guest date and time of arrival in column B and date and time left in C and he wants me to add a column that will calculate at any point if the guest occupancy reaches 9. I am stumped, any help would be greatly appreciated, thanks in advance.

Guest Name	Date & Time of arrival	Date and time of leaving	Time present
	28/08/2015 15:00	01/09/2015 13:35	03 22:35
	28/08/2015 15:30	04/09/2015 11:45	06 20:15
	30/08/2015 10:25	03/09/2015 12:30	04 02:05
	01/09/2015 19:00	05/09/2015 12:40	03 17:40
	02/09/2015 15:20	05/09/2015 12:40	02 21:20

<COLGROUP><COL style="WIDTH: 145pt; mso-width-source: userset; mso-width-alt: 7058" width=193><COL style="WIDTH: 145pt; mso-width-source: userset; mso-width-alt: 7058" width=193><COL style="WIDTH: 116pt; mso-width-source: userset; mso-width-alt: 5632" width=154><COL style="WIDTH: 122pt; mso-width-source: userset; mso-width-alt: 5924" width=162><TBODY>
</TBODY>

 

[zebturner]

im using Excel 2007 btw. thanks

 

[WarPigl3t]

I'm going to assume you mean you want to account for if time present is greater than or equal to 9. Use conditional formatting. >[9]:00:00

 

[zebturner]

I'm going to assume you mean you want to account for if time present is greater than or equal to 9. Use conditional formatting. >[9]:00:00

Thanks for the reply Warpigl3t, no what i want is a prompt that if at any time the total present in the hotel reaches 9 i want to be warned. imagine that you are looking at the spreadsheet at the end of the month and want to work out if at any point there were 9 guests present in the hotel.