## Bug description

The grouped-by-month view in charts is hella confusing. The x-axis shows a date that does not reflect the value on the y-axis.

1. the y-axis shows the number for the END of the month
2. the x-axis reads as "beginning of the month"

![CleanShot 2024-02-05 at 10 23 30@2x](https://github.com/PostHog/posthog/assets/35429197/d78df745-8319-4b78-95fa-d96f18aee357)

### Comparison with daily grouping

Compare the "group by month" view with "group by day". The x-axis labeling aligns with the y-axis values. 

![CleanShot 2024-02-05 at 10 29 20@2x](https://github.com/PostHog/posthog/assets/35429197/998825fa-7406-4214-8310-8f173980f80c)


## How to reproduce

1. Group a chart by month 
2. select "unique events"

## Proposal 

### 1. easy fix - remove the "1." from the labelling

- will still confuse readers with "is this the beginning or end of the month"

![CleanShot 2024-02-05 at 10 23 30@2x](https://github.com/PostHog/posthog/assets/35429197/1a0ae6d4-0e02-4b32-86ab-7b0e069655ed)

### 2. correct fix - show end of month

- removes ambiguity from "is that the beginning or end of month"
- harder to implement because months have different end days

![CleanShot 2024-02-05 at 10 23 30@2x](https://github.com/PostHog/posthog/assets/35429197/61226346-7f97-4bcd-87bf-53fc83c75245)


cc @jannesblobel
posthog/utils.py
groups = {}
        group_properties = {}
        person_properties = {}
        if request.user and request.user.is_authenticated:
            user = cast("User", request.user)
            person_properties["email"] = user.email
            person_properties["joined_at"] = user.date_joined.isoformat()
            if user.organization:
                groups["organization"] = str(user.organization.id)
                group_properties["organization"] = {
                    "name": user.organization.name,
                    "created_at": user.organization.created_at.isoformat(),
                }
        feature_flags = posthoganalytics.get_all_flags(
            posthog_distinct_id,
            only_evaluate_locally=True,
            person_properties=person_properties,
            groups=groups,
            group_properties=group_properties,
        )
        
        posthog_bootstrap["featureFlags"] = feature_flags
    
    
    
    context["posthog_bootstrap"] = json.dumps(posthog_bootstrap)
    context["posthog_js_uuid_version"] = settings.POSTHOG_JS_UUID_VERSION
    html = template.render(context, request=request)
    return HttpResponse(html)
def get_self_capture_api_token(request: Optional[HttpRequest]) -> Optional[str]: