Cumulative Addition with constraint

[JoeChanps]

[TABLE="class: grid, width: 500"]
<tbody>[TR]
[TD]Col.H
[/TD]
[TD]Col. L
[/TD]
[TD]Col. O
[/TD]
[TD]Date:
[/TD]
[TD]14.09.2018
[/TD]
[/TR]
[TR]
[TD]Date
[/TD]
[TD]Length
[/TD]
[TD]Cum. Length / Result
[/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]21.08.2018
[/TD]
[TD]4
[/TD]
[TD]4
[/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]25.10.2018
[/TD]
[TD]6
[/TD]
[TD]6
[/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]06.11.2018
[/TD]
[TD]8
[/TD]
[TD]14
[/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]29.11.2018
[/TD]
[TD]5
[/TD]
[TD]19
[/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]17.07.2018
[/TD]
[TD]9
[/TD]
[TD]13
[/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]01.08.2018
[/TD]
[TD]7
[/TD]
[TD]20
[/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]09.08.2018
[/TD]
[TD]12
[/TD]
[TD]32
[/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]22.08.2018
[/TD]
[TD]22
[/TD]
[TD]54
[/TD]
[TD][/TD]
[TD][/TD]
[/TR]
</tbody>[/TABLE]

Hey guys,

I need some help with a tricky problem and I have no clue how to solve it. Basically what I want is to accumulate the data with a constraint. So..
In Col. O are the results. Don't know if it's possible withou VBA?!

Every date that is before/equal 14.09.2018 should be accumulated (here the accum. dates are: 21.08.2018, 17.07.2018, 01.08.2018, 09.08.2018 and 22.08.2018).

And the other ones should be accumulated as well.

Thank you for your help.

With best regards
Joe

 

[Peter_SSs]

Like this?

Excel Workbook
	H	I	J	K	L	M	N	O	P	Q
1	Date				Length			Cum. Length / Result	Date:	14/09/2018
2	21/08/2018				4			4
3	25/10/2018				6			6
4	6/11/2018				8			14
5	29/11/2018				5			19
6	17/07/2018				9			13
7	1/08/2018				7			20
8	9/08/2018				12			32
9	22/08/2018				22			54
Cumulative length

 

[JoeChanps]

thx. i love you.

 

[Peter_SSs]

thx.

You're very welcome.

Just realised we could write the formula more simply though.

Excel Workbook
	H	I	J	K	L	M	N	O	P	Q
1	Date				Length			Cum. Length / Result	Date:	14/09/2018
2	21/08/2018				4			4
3	25/10/2018				6			6
4	6/11/2018				8			14
5	29/11/2018				5			19
6	17/07/2018				9			13
7	1/08/2018				7			20
8	9/08/2018				12			32
9	22/08/2018				22			54
Cumulative length

 

[JoeChanps]

Even better. I just have to understand the formula now, i.e. how it works. But you helped me a lot. I really appreciate it.