No definitive answer. "Mild" is one of those styles that has been hi-jacked by folk who have a distorted view of what it should be. Unfortunately they can often be the same folk who write the "style" guides. India Pale Ale, Stout, and especially Porter are some other old British beers that have been hi-jacked. It could happen because many UK breweries trashed their examples of these beers last century.
"Mild" originally meant "not stale" (aged), like porter that could have been aged in giant casks for over a year. So it was cheap! More so because the lack of aging meant less hops, which were expensive too.
But "Mild" outlived "Porter" past the world wars, although it suffered big cut-backs becoming the low-alcohol, low hopped beer of recent times. And as its popularity waned it often got "abused" at the hands of some unscrupulous landlords.
So, after that brief history: If you've bottled it you can sample the bottles after the usual two-three weeks. But some recipes try to hark back to older times and have higher OGs - these might better be left six weeks. But if it requires longer to become palatable, it isn't really "Mild" you've made.
"Mild" shouldn't be expected to keep long.
