That is, counting Saturday and Sunday's, which were both very chewy. Several unusual items of vocab in this one, and some canny cluing, took my time to 1'18". While the NW put up the most resistance, my mistake was in the SW.
1 BRAINPAN - I (one) in BRAN (refuse - noun) + PAN to give the first unusual (at least, for Limeys) item of vocab.
9 ABERRANT - very cunning, 'out' being the literal; R (king) + RAN in ABET.
10 EDGIER - LEDGER without the L (pounds down - we had 'down' for 'off' the other day) around I.
11 SOUNDPROOF - a double definition of sorts; some say one finds proofs only in logic, others in logic and pure mathematics. I stay out of it.
12 GNUS - my last in; just a DD ('latest sounds' translating to 'sounds like "news"'), even if I was looking for a word ending in S, where the S was taken from animalS.
13 FIANCHETTO - FIANCE[e] + an anagram* of OF THE to give another chess move, this time 'the development of a bishop by moving it one square to a long diagonal of the board' - whatever that means. I was envisaging someone in Dante's third circle of Hell, but, alas, no.
16 GAMELAN - ME in GALA + [productio]N to give a Javanese/Balinese instrumental ensemble that makes a lot of noise.
17 COSTARD - COSTAR + [finishe]D to give a cooking apple which I'd forgotten.
20 BOTTLENECK - double definition; easy enough, but not for me, having been ground down by the others.
22 AIDE - smart this; it's the middle letters of [m]AIDE[n].
23 LAY CLAIM TO - another cunning clue with a well hidden anagram of L[arge] + CALAMITY + O[ld], which leaves 'bag' as the literal.
25 WARDEN - first letter of W[illiam] + ARDEN (once a forest in the Heart of England - now mainly Birmingham); Collins for 'warden' has '3. a person employed to patrol a national park or safari park' - before it becomes Legoland, presumably.
26 NEUTRINO - NEU (sounds like 'new') + TRI (ditto 'tree') + NO (ditto 'know') to give the naughty peeps who use two computers to record times of 1' 50" on the leader board, which is usually enough to beat Mark Goodliffe. Neither of the two dictionaries I consulted mentioned a lack of charge, but perhaps that follows of itself when you are 'a neutral subatomic particle with a mass close to zero and half-integral spin, which rarely reacts with normal matter'. Substitute 'people' for 'matter' to get the cruciverbal variety.
27 NURSLING - RUN (work) reversed + SLING. Very nice.
2 RED PANDA - NAP (sleep) in ADDER (snake) both reversed.
3 IRIDESCENT - indiscreet*.
4 PERSIFLAGE - quite the toughie this; it's I (one) + FLAG (standard) in the PERSE School, Cambridge. The sort of thing those 'flyting' poets in late 15th century Scotland got up to, typically with aspersions about the other chap's manhood. Medieval 'sledging', if you will.
5 NATURAL - a simple cryptic definition which held me up.
6 WELD - L[eft] in WED[nesday].
7 RAGOUT - AG in ROUT for a culinary creation I've heard of.
8 STAFFORD - O (no) + RD (way) on STAFF.
14 CLOCK TOWER - the literal is 'high time here...?' and the wordplay a cringeworthy 'one pulls a face', where TOWER must be taken as if it's, say, a tug. Better not to explain further, I think.
15 EXTRAMURAL - another DD of sorts; 'another painting' is rather good.
16 GOBBLING - 'taking fast food' in the sense of taking one's food [too] fast; GOB is British slang for mouth and BLING comes up most weeks now for the kind of stuff chavs wear.
18 RED QUEEN - an allusion to Alice through the Looking Glass.
19 NEW MOON - the literal is 'start of the month for some', as the Buddhist, Hebrew Hindu and Muslim calendars start with the crescent moon, but not others, for example, the Chinese or the Gregorian calendar; it's WOMEN* + ON (forward).
21 THYMUS - my wrong 'un; it's THY (your) + MUS[e] for the 'lymphoid organ situated in the neck which becomes much smaller at the approach of puberty'; I had 'thyrus', with a truncated RUS[h] and a prayer.
24 ARID - A + RID[e]; finally, an easy one.