Object assignment with only one start date and end Date in the same column

Hello everyone,

I have two documents, in the first document is the start date and the name of the object and in the second document is the power consumption for each day. Now I have to connect the two documents so that I can prove in the second document which object has used the power at what time.

e.g.:

second Docmuent:

So as you can see I only have the start date, the start date of the next object is also the end date.

The first Dokumnet looks like that:

I already created the column Start Date with "lookupvalue" and now I just have to create a column containing the object name. I would like to do this because I want to calculate the average power consumption per object.

Many thanks in advance!

Greetings Luaks