Describe the bug
I want to use half hour configutaion for top ruler but it doesn't work. I have configured it for hours and it works.

To Reproduce
Steps to reproduce the behavior:
PMEMV= {};
PMEMV.type = "bar";
PMEMV.startDatetime = dtInici;
PMEMV.endDatetime = dtFi;
PMEMV.scale = "half-hour";
PMEMV.rows = "auto";
PMEMV.minGridSize=720; //48
PMEMV.headline = {};
PMEMV.headline.display=true;
PMEMV.headline.title=strEspai;
PMEMV.headline.range=false;
PMEMV.headline.locale="ca-ES";
PMEMV.headline.format={};
PMEMV.headline.format.timeZone="Europe/Madrid";

    PMEMV.sidebar = {};
    PMEMV.sidebar.sticky=true;
    PMEMV.sidebar.list=[];
    
    PMEMV.ruler={};
    PMEMV.ruler.top={};
    PMEMV.ruler.top.lines=["year","month","day","weekday","hour","half-hour"];
    PMEMV.ruler.top.height=26;
    PMEMV.ruler.top.fontSize=13;
    PMEMV.ruler.top.color="#777777";
    PMEMV.ruler.top.background="#FFFFFF";
    PMEMV.ruler.top.locale="ca-ES";
    PMEMV.ruler.top.format={};
    PMEMV.ruler.top.format.timeZone="Europe/Madrid";
    PMEMV.ruler.top.format.hour12=false;
    PMEMV.ruler.top.format.year="numeric";
    PMEMV.ruler.top.format.month="long";
    PMEMV.ruler.top.format.day="numeric";
    PMEMV.ruler.top.format.weekday="long";
    PMEMV.ruler.top.format.hour="numeric";
    PMEMV.ruler.top.format.halfhour="numeric";
    
    
    PMEMV.rangeAlign="begin";
    PMEMV.eventMeta={};
    PMEMV.eventMeta.display=true;
    PMEMV.eventMeta.scale="half-hour";
    PMEMV.eventMeta.locale="ca-ES";
    PMEMV.eventMeta.format={};
    PMEMV.eventMeta.format.timeZone="Europe/Madrid";
    PMEMV.eventMeta.content="";
    PMEMV.reloadCacheKeep=false;
    PMEMV.zoom=false;
    PMEMV.debug=false;    

Expected behavior
represent events in half-hour scale

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: [Windows10]
• Browser [edge]
• Version [123.0.2420.97 64bits]

Additional context
Console fires following error :
jquery.timeline.min.js:10 Uncaught (in promise) TypeError: Property "grids" cannot set because undefined or invalid variable.
at t.value (jquery.timeline.min.js:10:11326)
at t. (jquery.timeline.min.js:10:7686)
at u (jquery.timeline.min.js:1:61583)
at Generator._invoke (jquery.timeline.min.js:1:61336)
at Generator.next (jquery.timeline.min.js:1:61942)
at p (jquery.timeline.min.js:1:80361)
at a (jquery.timeline.min.js:1:80564)
at jquery.timeline.min.js:1:80623
at new Promise ()
at t. (jquery.timeline.min.js:1:80504)

Thank you very much. Great work!