People staying up late, close to Wales, oddly (5,4)
I believe the answer is:
night owls
'people' is the definition.
(night owl is a kind of person)
'close to wales oddly' is the wordplay.
'close' becomes 'nigh' (similar in meaning).
'oddly' means one should take alternating letters (letters in the odd-numbered positions are used).
The alternate letters of 'wales' are 'wls'.
'nigh'+'to'+'wls'='NIGHT OWLS'
'staying up late' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Another definition for night owls that I've seen is " Sharp-eyed types".)