# Difference between --date-order and reverse chronological order?

3 messages from 2011-04-27 to 2011-04-27. Participants: Dun Peal, Junio C Hamano, Johannes Sixt.
Thread: https://gitlist.dev/t/27201

## Dun Peal, 2011-04-27 15:15

Subject: Difference between --date-order and reverse chronological order?
Message-ID: <12e0244a-313e-4d67-9b91-c0d443276cff@k7g2000yqj.googlegroups.com>
URL: https://gitlist.dev/e/12e0244a-313e-4d67-9b91-c0d443276cff%40k7g2000yqj.googlegroups.com

```
Hi.

The git-log manpage defines --date-order:

"This option is similar to --topo-order in the sense that no parent
comes before all of its children, but otherwise things are still
ordered in the commit timestamp order."

But by Git's definition, for a child commit to be created, its parent
must already exist. So even in reverse chronological order, all
parents should come after all their children, no?

Thanks, D.

```

## Junio C Hamano, 2011-04-27 17:36

Subject: Re: Difference between --date-order and reverse chronological order?
Message-ID: <7v7haf8ulj.fsf@alter.siamese.dyndns.org>
URL: https://gitlist.dev/e/7v7haf8ulj.fsf%40alter.siamese.dyndns.org
In-Reply-To: <12e0244a-313e-4d67-9b91-c0d443276cff@k7g2000yqj.googlegroups.com>

```
Dun Peal <dunpealer@gmail.com> writes:

> But by Git's definition, for a child commit to be created, its parent
> must already exist. So even in reverse chronological order, all
> parents should come after all their children, no?

I think "distributed" and "your clock may be skewed" would solve that
puzzlement ;-)

```

## Johannes Sixt, 2011-04-27 19:39

Subject: Re: Difference between --date-order and reverse chronological order?
Message-ID: <4DB87106.9030209@kdbg.org>
URL: https://gitlist.dev/e/4DB87106.9030209%40kdbg.org
In-Reply-To: <7v7haf8ulj.fsf@alter.siamese.dyndns.org>

```
Am 27.04.2011 19:36, schrieb Junio C Hamano:
> Dun Peal <dunpealer@gmail.com> writes:
> 
>> But by Git's definition, for a child commit to be created, its parent
>> must already exist. So even in reverse chronological order, all
>> parents should come after all their children, no?
> 
> I think "distributed" and "your clock may be skewed" would solve that
> puzzlement ;-)

Are you saying that given this history:

      E----D
    /     /
   A--B--C

* we can get D-C-B-E-A or D-E-C-B-A with --topo-order

* we can get the above plus D-C-E-B-A with --date-order

* and with neither --topo-order nor --date-order we can also get
D-E-A-C-B or D-C-B-A-E if there was sufficient clock skew when the
commits were created. How would such a clock skew have looked like?

-- Hannes

```