It's been a month already! Very generous Saturday puzzle to mark the occasion. Lots of anagrams, little bit of an apt pair with STARRY EYED and BROKEN HEARTED.

Across

1

No-one it'll cast out of a group of stars (13)
CONSTELLATION — anagram (out) of NO ONE IT'LL CAST

10

Expert at holding a lot of fish fingers? (3,4)
DAB HAND — cryptic def.

11

Yew, say, made up part of lexicon, if erroneously (7)
CONIFER — hidden in lexiCON IF ERroneously

12

Put on the record before saint flips sides and plays host (10)
ENTERTAINS — ENTER (put on the record) TAINS (saint swapping first and last letters)

13

Swimming pool game (4)
POLO — anagram (swimming) of POOL

15

Counter blow (6)
BUFFET — double def.

17

Porters at Spooner's underworld dances ... (8)
BELLHOPS — Spoonerism of HELL (underworld) BOPS (dances)

19

... ran through claret after weeks of debauchery (8)
SKEWERED — anagram (debauchery) of WEEKS, RED (claret)

20

Got wind of hero of Shakespeare's midwinter (6)
LEARNT — LEAR (hero of Shakespeare's) NT (middle letters of winter)

23

Somalia's heart land (4)
MALI — hidden in soMALIa

24

Stifle and hold back favourite member of the family (10)
STEPMOTHER — SMOTHER (stifle) containing reversal (back) of PET (favourite)

27

Lionises game reserve (7)
REVERES — anagram (game) of RESERVE

28

A crafty role in aircraft control (7)
AILERON — A, anagram (crafty) of ROLE IN

29

On one's uppers there and melting down in the dumps (6-7)
BROKEN-HEARTED — BROEK (on one's uppers), anagram (melting) of THERE AND

Down

2

Circle interior of exterior bits (5)
ORBIT — hidden in exteriOR BITs

3

Romantic stay in awfully seedy housing (6-4)
STARRY-EYED — anagram (awfully) of SEEDY around TARRY (stay)

4

Bring closer to complete attention (6)
ENDEAR — END (complete) EAR (attention)

5

Parasites seen troubling mine host (8)
LICENSEE — LICE (parasites) anagram (troubling) of SEEN

6

Brazil, say, backed up a bluefin, say (4)
TUNA — reversla (backed up) of NUT (Brazil, say), A

7

Queasy or sleazy? (3-6)
OFF-COLOUR — double def.

8

Raved hysterically over second part of speech (6)
ADVERB — anagram (hysterically) of RAVED, B (second)

9

New wars or old weapons (6)
ARROWS — anagram (new) of WARS OR

14

Manual adding ultramarine to most of greens (4-6)
BLUE-COLLAR — BLUE (ultramarine) COLLARd (greens, without last letter)

16

Glutton for complimentary offal (4-5)
FREE-LIVER — FREE (complimentary) LIVER (offal)

18

Scrap from jumbo is lying within 1000kg limits (8)
JETTISON — JET (jumbo), IS inside TON (1000kg)

19

Painful to keep doctor in the dark (6)
SOMBRE — SORE (painful) around MB (doctor)

21

Can threes split into two and ace? (6)
THRONE — THR (first half of threes), ONE (ace)

22

Party drug stashed under patio turned out to be narcotic (6)
OPIATE — anagram (turned) of PATIO, E (party drug)

25

Sixth or seventh to cover charger (5)
HORSE — hidden in sixtH OR SEventh

26

Extended stage set for the weekends (4)
TREK — last letters of seT foR thE weeK