French phrase I haven't heard before - when to use?

[Veronica]

We have received an invitation to a French wedding and there is a phrase in the invite :

"mettre sure votre 31".

 

it is an informal invite, written by a young couple in their 20s and I was wondering if this is a current phrase and when it would be used.   I have taken it as a jokey phrase a bit like 'dressing up to the 9's'. 

 

Someone has suggested that it is an old-fashioned phrase but I would quite like to know it would make me sound old-fashioned to use it... perhaps a bit like school french?

 

 

 

 

[Neil Coffey]

Hi Veronica -- that's the idea, very similar to English "dressed up to the 9s". I think the full phrase is usually se mettre sur son trente-et-un, though you could also say e.g. Elle est sur son trente-et-un.

Funny how French chooses 31 and English chooses 9...

[Veronica]

Thank you, Neil. Do you happen to know if this is an old-fashioned phrase or not?

[Roland Jondeau]

The phrase is not old fashioned. On ly the use.

[Sonny Faolan]

Hi. I am not familiar with this phrase either, but I have found a pretty convincing and interesting explanation on "linternaute" - which I find very reliable : ]

here's the link to the page:

http://www.linternaute.com/expression/langue-francaise/49/se-mettre...

peace.

[Veronica]

thank you Sonny, it is an interesting explanation - and a very useful website which I did not know of.
many thanks

[Roland Jondeau]

1 - "Se mettre sur son 31" est exactement construit comme "endimanché", et signifie qu'on s'est habillé "comme pour une cérémonie", en opposition à l'idée opposée: "Venez comme vous êtes", "sans cérémonie".
L'acte de "se mettre sur son 31", ou de "s'endimancher" peut être jugé désuet, mais pas la formuel qui le désigne.