Specifying a time with bookmarks.

I would like to be able to specify the time for an update as I don't always have access to twitter when I'm reading, for example when travelling and especially when on a plane. This would allow me to note the times myself and enter them later.

This may sound like too much effort for a person to put in, but I'm actually developing a mobile app for updating bkkeepr and so it would be possible for me to continue marking bookmarks in this and then have it upload them later.

(I realise you're aware of this already as I've contacted you directly but thought I'd add it here as I couldn't see an existing entry)