## 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
"""Return a number in a compact format, with a SI suffix if applicable.
    Client-side equivalent: utils.tsx#compactNumber.
    """
    value = float(f"{value:.3g}")
    magnitude = 0
    while abs(value) >= 1000:
        magnitude += 1
        value /= 1000.0
    return f"{value:f}".rstrip("0").rstrip(".") + ["", "K", "M", "B", "T", "P", "E", "Z", "Y"][magnitude]
def is_postgres_alive() -> bool:
    from posthog.models import User
    try:
        User.objects.count()
        return True
    except DatabaseError:
        return False
def is_redis_alive() -> bool:
    try:
        get_redis_info()
        return True
    except BaseException:
        return False
def is_celery_alive() -> bool:
    try:
        return get_celery_heartbeat() != "offline"
    except BaseException:
        return False
def is_plugin_server_alive() -> bool: