Power Query chose a value <=date

[ursua]

Hi,
I have towo tables in excel, a source table and a destination table. In a source table there is a number, a timestamp and a value. In destination table there is a number, timestamp.
Source table:

Number	Datestamp	value
1​	2023-07-24 11:15:40​
1​	2023-07-24 11:15:40​	A/S/S
1​	2023-07-24 11:15:40​	A/S/S
1​	2023-07-25 09:57:33​	A/S/M
1​	2023-07-25 09:57:33​	A/S/M
1​	2023-07-25 09:57:33​	A/S/M
1​	2023-08-01 18:52:30​	A/S/S
1​	2023-08-01 18:52:30​	A/S/S
1​	2023-08-01 18:52:30​	A/S/S
1​	2023-09-07 17:05:35​	A/S/X
1​	2023-09-07 17:05:35​	A/S/X
1​	2023-09-07 17:05:35​	A/S/X
1​	2023-09-20 08:07:50​	B/C/X
1​	2023-09-20 08:07:50​	B/C/X
1​	2023-09-20 08:07:50​	B/C/X
1​	2023-10-16 12:27:20​	A/S/S
1​	2023-10-16 12:27:20​	A/S/S
1​	2023-10-16 12:27:20​	A/S/S
1​	2023-12-01 08:45:00​	B/C/Z
1​	2023-12-01 08:45:00​	B/C/Z
1​	2023-12-01 08:45:00​	B/C/Z
1​	2023-12-22 15:39:30​	B/C/F
1​	2023-12-22 15:39:30​	B/C/F
1​	2023-12-22 15:39:30​	B/C/F
1​	2023-12-28 12:25:00​	A/S/S
1​	2023-12-28 12:25:00​	A/S/S
1​	2023-12-28 12:25:00​	A/S/S

and a destination

Number	Created ab	Created	value
1​	2023-07-24 10:56:55​	2024-04-15 13:39:25​
1​	2023-07-24 10:56:55​	2024-04-17 10:35:45​
1​	2023-07-24 10:56:55​	2024-04-17 12:05:00​
1​	2023-07-24 10:56:55​	2024-04-17 15:07:25​
1​	2023-07-24 10:56:55​	2024-04-18 12:01:50​
1​	2023-07-24 10:56:55​	2024-04-18 13:16:20​
1​	2023-07-24 10:56:55​	2024-04-21 18:39:45​
1​	2023-07-24 10:56:55​	2024-04-22 10:59:10​
1​	2023-07-24 10:56:55​	2024-04-24 11:29:31​
1​	2023-07-24 10:56:55​	2024-04-24 18:15:40​
1​	2023-07-24 10:56:55​	2024-04-26 14:55:40​
1​	2023-07-24 10:56:55​	2024-04-26 15:43:45​

What i need to achieve is to put a value from source to destination for every number (of course there are more than just a 1) depending on timestamp. the timestamp from source should be equal or first one before the created timestamp in destination. wouldn't be a problem if the timestamps were exactly the same (simple merge then) but how to achieve it with < or = ?

 

[AlienSx]

    // your tables are destination_table and source_table
    rename = Table.RenameColumns(destination_table, {"Created", "Datestamp"}),
    cmb = Table.Sort(rename & source_table, {"Number", "Datestamp", "Created ab"}),
    fill_up = Table.FillUp(cmb,{"value"}),
    filter = Table.SelectRows(fill_up, each ([Created ab] <> null))