The problem is in the lastret.txt.
http://www.mesquiteweather.net/sivu2.php not only shows no graphs, all the tabs below the graphs are empty excluding the first one.
Where comes the data on sivu2.php from:
The icons on top => plaintext.txt
All graphs tabs => lasteret.txt
Overview tab => plaintext.txt
Hour-by-Hour / Detailed and grass&soil from lastret.txt
lastret.txt is not processed correctly, probably contains no data needed by the 3in1.
So there is no startdate which gives the error, but which is irrelevant as there is no data to graph.
The plaintext.txt and lasteret.txt are both located in your wxsim folder.
I copied both files to my PC, installed 3in1 script (checked, seems same version as yours)
Your plaintext.txt and lastret => No graphs and no extra tabs.
Run your plaintext.txt with my lastret.txt => all output is there.
===
Compared your lastret.txt and mine.
Only difference is in the times. Yours are not on the full hour but five minutes off.
Last field on every data line is the UTC time which contains
2015-01-05_19:00_UTC in lastret from me
2015-01-05_16:55_UTC in yours.
===
I enclose the lastret.txt which works at my place and named is lastret eu.txt
You could do the folowing test.
1. upload lastret eu.txt to your wxsim folder
2. rename it to lastret.txt
3. run sivu2.php
The graphs should be drawn, all tabs should contain data.
If the graphs are OK => you have to make a change in wxsim on your pc
If the graphs fail again, the script can not locate the lastret.txt file and we have to check the settings, tomorrow my time in the 3in1 scripts. As all error reporting is surpressed it will take some time.
Wim