A happy birthday to all you leaplings. A generally straightforward puzzle from Pedro today with just a couple of clues (e.g. 1A, 8A) requiring a bit of head-scratching/eye-narrowing/lip-pursing.
The crossword can be found here if the usual channels are unavailable: http://feeds.thetimes.co.uk/puzzles/crossword/20160229/13697/
Definitions are underlined.
Across
1
Peer half-heartedly supporting church out of necessity (8)
PERFORCE - PER (Peer half-heartedly, i.e. the word "peer" with only one of its middle e's) + FOR (supporting) + CE (church). Not the commonest word, and probably not the easiest entry point for the puzzle.
5
Nothing from first bit of zinc aggregate returned (4)
ZERO - Z (first bit of zinc, i.e. the first letter of the word "zinc") + reversal (returned) of ORE (aggregate)
8
Common person that is to be back in scheme (8)
PLEBEIAN - reversal (back) of IE (that is) + BE, in PLAN (scheme). Quite a complex construction as the "to" in the clue needs to be interpreted as "beside". The kind of horrendous combo of vowels that makes you glad of the wordplay. To my great surprise, it doesn't look as though this word has appeared in a Times puzzle in the last decade (though the common shortening to pleb has cropped up several times).
9
Judge with a Parisienne for thirty days (4)
JUNE - J (Judge) + UNE (a Parisienne, i.e. the word "a" for a resident of Paris - the female Parisienne gives us an extra hint to look for the female form of "a")
11
Specific rail-car put out (10)
PARTICULAR - anagram (out) of RAIL-CAR PUT
14
Notes my accepting unemployment benefit returned (6)
MELODY - MY around (accepting) reversal (returned) of DOLE (unemployment benefit)
15
Point about sparkling wine: not much good now? (4,2)
PAST IT - PT (Point) about ASTI (sparkling wine)
17
Arrangement of music - key of A, not C, in my opinion (2,3,3,2)
IF YOU ASK ME - anagram (Arrangement) of MUSI{c} KEY OF A, where the "not C" tells us to omit the letter c from the anagram fodder
20
Article caught like a fish? That's ingenious (4)
NEAT - A (Article) in NET - if something is in a net then it's caught like a fish.
21
TV programme possibly caps tucking into food (4,4)
CHAT SHOW - HATS (possibly caps) inside (tucking into) CHOW (food)
22
Regret backing old currency (4)
EURO - reversal (backing) of RUE (Regret), + O (old)
23
Silver reflected faint source of illumination (8)
GASLIGHT - reversal (reflected) of AG (Silver, i.e. the chemical symbol for silver), + SLIGHT (faint)
Down
1
Wind instrument, one joining piano in exercises (4)
PIPE - I (one) + P (piano), in PE (exercises)
2
Scottish dance about to be supported by the Spanish (4)
REEL - RE (about) + EL (the Spanish, i.e. a Spanish word for "the"). The "to be supported by" simply says that the RE is to go on top of the EL, since it's a down clue.
3
Obvious, with OU intervening, transmission ended! (4,3,4)
OVER AND OUT - AND (with) + OU, inside (intervening) OVERT (Obvious). Chambers tells me that OU can be Open University or Oxford University but either way the surface is somewhat oblique.
4
Decent participants in match as televised (6)
CHASTE - hidden (participants) in matCH AS TElevised
6
Impartiality of energy standard (8)
EQUALITY - E (energy) + QUALITY (standard)
7
Think too much of a concern for cricket umpires? (8)
OVERRATE - the over rate refers to the speed at which bowlers get through their overs in a game of cricket. Teams can be fined if they are too slow - it is up to the umpires to determine the over rate achieved, taking into account various factors such as injuries, whether the batting side has been time-wasting, etc.
10
Waste material spoiled smart place (5-5)
SCRAP-METAL - anagram (spoiled) of SMART PLACE
12
Mood displayed by a doctor having treated niece (8)
AMBIENCE - A + MB (doctor) + anagram (treated) of NIECE
13
Follow the rules: quiet song followed by loud tune (4,4)
PLAY FAIR - P (quiet) + LAY (song) + F (loud) + AIR (tune). An interesting way to break down the answer.
16
Article on complex maths leads to complaint (6)
ASTHMA - A (Article) + anagram (complex) of MATHS
18
Yank throttling husband is ruffian (4)
THUG - TUG (Yank) around (throttling) H (husband)
19
Didn't stand around waiting initially for strike (4)
SWAT - SAT (Didn't stand) around W (waiting initially, i.e. the first letter of the word "waiting")