How to sort files correctly?

[kruger]

Hello.

My problem is that I am adding files from different dates ranges but I want them to be sorted by the date. The date is not in the files properties - it is written in particular file (scanned pdf).
I tried to add date to the file name - doesnt worki
Currently I am giving every file a count number before the name (1. Contract blabla, 2. New contract blabla). But when my count goes up to ten the sorting system uses only first letter (so for example 11 will be higher then 9)
it looks like this:
1
10
11
12
2
3
4
5
6
7
8
9

Any tips on how can I sort my files by date (I cant sort by date that I aded this file)?

[vamirr]

My test engineers have the same problem.   They have test notebooks that are required to have a certain structure.  They've resorted to using alpha characters to prefix their folder names so that the sort works like they want.

A. Test Program & Requirements
B. Instrumentation
C. Calibration

etc.