Used layout: Timeseries All.

function formatTooltipAsHours(value, ratio, id, index)
{
    return value.toFixed(2) + ' h';
}
 
function formatQuarter(d)
{
    if (d instanceof Date)
    {
        var q = d.getMonth();
        q = parseInt(q / 3) + 1;
        return 'Q' + q;
    }
    return '';
}
 
function formatHalfyear(d)
{
    if (d instanceof Date)
    {
        var q = d.getMonth();
        q = parseInt(q / 6) + 1;
        return 'H' + q;
    }
    return '';
}
 
var c3arg = {
    onrendered: updateFrameHeight,
    data: chartData,
    grid: {
        y: {
            show: true
        },
        x: {
            show: true
        }
    },
    axis: {
        x: {
            type: 'timeseries',
            label: {
                text: chartData.custom.xLabel,
                position: 'outer-left'
            },
            tick: {
                format: eval(chartData.custom.xTickFormat),
                culling: {
                    max: 25
                },
                fit: true,
                multiline: false
            }
        },
        y: {
            label: chartData.ytype
        }
    }
};
 
if (chartData.custom && chartData.custom.tooltip)
{
    var tooltipFunction = eval(chartData.custom.tooltip);
    c3arg.tooltip = {
        format: {
            value: tooltipFunction
        }
    };
}
 
if ( chartData.custom && chartData.custom.gauge_max)
{
    c3arg.gauge = {
        max: parseFloat(chartData.custom.gauge_max)
    };
}
 
c3.generate(c3arg);

import java.lang.reflect.Field;
import java.math.BigDecimal;
 
import org.apache.lucene.document.Document;
 
import com.atlassian.jira.component.ComponentAccessor;
import com.atlassian.jira.issue.DocumentIssueImpl;
import com.atlassian.jira.issue.Issue;
import com.atlassian.jira.issue.worklog.Worklog;
import com.atlassian.jira.issue.worklog.WorklogManager;
import com.atlassian.jira.jql.parser.JqlParseException;
import com.atlassian.jira.jql.parser.JqlQueryParser;
import com.atlassian.query.Query;
import com.atlassian.jira.util.I18nHelper;
 
import com.decadis.jira.xchart.api.ChartParam;
import com.decadis.jira.xchart.api.model.Period
import com.decadis.jira.xchart.api.util.DateUtils;
 
def i18n = ComponentAccessor.getJiraAuthenticationContext().getI18nHelper();
def wlm = ComponentAccessor.getWorklogManager();
def metaCountGroup = chartBuilder.newDataCollector();
 
JqlQueryParser jqlQueryParser = ComponentAccessor.getComponent(JqlQueryParser.class);
Query query = null;
 
Period selectedPeriod = Period.fromString(TimePeriod);
try
{
  query = jqlQueryParser.parseQuery(JQL);
} catch (JqlParseException e)
{
  throw new IllegalArgumentException("Bad JQL: " + jql);
}
 
def groupValueExtractor = chartBuilder.getGrouper(GroupBy);
Field documentField;
try
{
  documentField = DocumentIssueImpl.class.getDeclaredField("document");
  documentField.setAccessible(true);
  for ( Issue issue : chartBuilder.getFilterUtils().performSearch(query, user) )
  {
    Document doc = (Document) documentField.get(issue);
    for ( Worklog wl : wlm.getByIssue(issue) )
    {
      String x = dateUtils.getPeriodGroup(wl.getCreated(), selectedPeriod);
      BigDecimal value = BigDecimal.valueOf(wl.getTimeSpent()).divide(BigDecimal.valueOf(3600), 4, BigDecimal.ROUND_HALF_UP);
      for ( String group : groupValueExtractor.getGroups(doc) )
      {
        metaCountGroup.addValue(value, group, x);
      }
    }
  }
} catch (Exception e){}
 
metaCountGroup.fillMissingValues();
def chartData = chartBuilder.newChartData(i18n.getText("common.concepts.time.spent"));
for ( String grpKey : metaCountGroup.keySet() )
{
  chartData.addGroupName(grpKey, groupValueExtractor.getResolvedValue(grpKey, null));
}
 
chartData.setxFormat("%Y.%m.%d");
chartData.setPeriod(selectedPeriod);
chartData.setType(ChartType);
chartData.addCustomData("tooltip", "formatTooltipAsHours");
 
chartBuilder.getChartUtil().transformResult(metaCountGroup, chartData, true);
 
return chartData;