Hi Ryan,

Please try the below code.

VF Page
<apex:page controller="AccountRec_Barchart" docType="html-5.0" title="Bar chart" >
    <apex:form >
        
        <apex:outputText value="from Date">
        </apex:outputText>
        <apex:input type="date" value="{!fromdate}"/>
        <apex:outputText value="ToDate"></apex:outputText>
        <apex:input type="date" value="{!todate}" />
        <apex:commandButton value="submit" action="{!submit}" reRender="chartid" />
        
    </apex:form>
    
    <apex:chart id="chartid" height="300" width="650" data="{!data}" colorSet="2A98DC"  resizable="true" >
        
        <apex:axis type="Numeric" position="left" fields="count" title="Recordcount" minimum="0" grid="false" />
        <apex:axis type="Category" position="bottom" fields="billingcityname" title="billingcity"  />
        <apex:barSeries orientation="vertical" axis="left" xField="billingcityname" yField="count">
            
        </apex:barSeries>
        
    </apex:chart>  
</apex:page>

Controllor

public class AccountRec_Barchart
{
    public date fromDate{set;get;}
    public date todate{set;get;}
    public list<aggregateresult> listaggregate= new list<aggregateresult>();
    public list<barchartdata> lb = new list<barchartdata>();
    
    public void submit()
    {
        listaggregate = [select name, COUNT(Id) n
                         from Account 
                         where createddate > : fromDate and createddate <:todate
                         group by name
                        ];
    }
    
    public barchartdata[] getdata()
    {   
        system.debug('getdata');
        barchartdata[] datachart = new barchartdata[]{};
            
            for(aggregateresult a :listaggregate)
        {
            datachart.add(new barchartdata(a));     
        }
        return datachart;
    }
    
    // wrapper class 
    public class barchartdata
    {
        public string name {set;get;}
        public  integer count{set;get;}
        
        barchartdata(aggregateresult result)
        {
            this.count = (Integer) result.get('n');
            this.name = (string) result.get('billingcity');           
            
        }
    } 
}

In controllor you can replace the created date field with your custom date field.

Thanks,
Saroja
Sweet Potato Tec