Ancient dates in Gantt charts (or other timelines)

[piperoc]

Description

I would like to create a Gantt of events that occurred in the ancient past, where the date would fall in the Before Common Era (BCE).
I tried various ways but could not find any information or a way to do this.

The markdown would look something like:

gantt
    title Roman Kings Timeline
    dateFormat  YYYY
    axisFormat %Y

    Romulus: rm, 753 BCE, 37y
    Numa Pompilius: np, 715 BCE, 42y
    Tullius Hostilius: th, 673 BCE, 32y

Of course, this does not work since I do not know whether there is a syntax for such use case.
Maybe it is not possible.

Steps to reproduce

1. type the following in the Live editor:

gantt
    title Roman Kings Timeline
    dateFormat  YYYY
    axisFormat %Y

    Romulus: rm, 753 BCE, 37y
    Numa Pompilius: np, 715 BCE, 42y
    Tullius Hostilius: th, 673 BCE, 32y

2. No diagram is displayed, but also no error is reported by the editor.

Screenshots

No response

Code Sample

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Setup

• Mermaid version:
• Browser and Version: [Chrome, Edge, Firefox]

Suggested Solutions

No response

Additional Context

No response

[piperoc]

I have the feeling that the limitation might be to the Unix Timestamp which only counts from 1/1/1970...

[piperoc]

Someone answered me on StackOverflow so I used the JavaScript notation for "negative" dates. Here's what I got.

gantt
    title Roman Kings Timeline
    dateFormat  YYYY
    axisFormat %Y BCE

    Romulus: rm, -00753, 37y
    Numa Pompilius: np, -00715, 42y
    Tullius Hostilius: th, -00673, 32y

Which is not perfect but at least it's more accurate.

I don't know if there is an idea for the year out format, which is not a showstopper anyway.

[jgreywolf]

Closing as duplicate of #4437