The current minimum doesn't account for a stores that have a warehouse nearby or multi-stores that have daily replens.

The quick fix would be to add 0 as an option, the current lowest time is 1 day if an item is in one store that needs transfering to another.

Alternatively Multi Bin Locations which is in another post.

For example all our shoe size variations are kept in the warehouse (same building) so it looks confusing and we don't want to deter customers form coming to the shop, thinking that they cannot collect their size or any other product that's in the larger warehouse the same day.

We've done it this way round because we couldn't have an item in more than one bin location.