A couple of tricky ones to parse. Thanks to Poins for an enjoyable puzzle. Definitions are underlined in the clues.
Across
1 Types of information needed on time (6)
GENERA : GEN(information) plus(needed on) ERA(a long period of time).
5 Fake gun as fashion accessory once (8)
CODPIECE : COD(fake) + PIECE(informal term for a firearm, say, a gun).
Defn: … worn over the male genitals, in the 15C and 16C, “cod” being Middle English for “scrotum”.
9 Lofty reportedly tolerated having noble parents (8)
HIGHBORN : HIGH(lofty) + homophone of(reportedly) “borne”(past participle of “bear”;to endure;tolerate).
10 Extremely annoyed after soldier captures the heart of confessed bacchante (6)
MAENAD : The 1st and last letters of(Extremely) “annoyed” placed after(after) [ MAN(a soldier) containing(captures) the central letter of(the heart of) “confessed“.
Defn: A female follower of Bacchus, the mythological god of wine and giver of ecstasy (not the pills, though).
11 Quick to respond to urge (6)
PROMPT : Double defn.
12 Fortify even parts of Reims before a town in the south (8)
EMBATTLE : The 2nd and 4th letters(even parts of) “Reims” plus(before) BATTLE(a town in the south of England, in East Sussex to be more specific).
Defn: … a place or building against attack.
14 Crazy to be honest at that time about live data’s source (5,3,4)
ROUND THE BEND : ROUND(not omitting anything;frank;honest, as in “a round scolding” + THEN(at that point in time) containing(about) BE(to live;to exist) + the 1st letter of(…’s source) “data“.
18 In which you may recognise Pollock’s abusive language (12)
BILLINGSGATE : Cryptic defn: So-named from Billingsgate, the London fish market (where you might buy pollocks, a food fish) notorious for the foul language used there.
22 Perfect finish (8)
COMPLETE : Double defn.
25 Fully understand contract (4,2)
TAKE IN : Double defn: 2nd: To alter an article of clothing, making it smaller.
26 What’s entertaining about stopping a princess finding a handsome young man? (6)
ADONIS : AS(what, as in “do as you wish”) containing(entertaining) [ ON(about, as in “the talk was on the law”) contained in(stopping) DI(the late Princess Diana) ].
27 Material Circe evens out with a weight (8)
CRETONNE : “Circe” minus its 2nd and 4th letters(evens out) plus(with) TONNE(a unit of weight equivalent to 1000 kilograms).
Defn: … of heavy cotton with colourfully printed patterns, used especially for furnishings.
28 What Puck uses in an instant assuming Nick’s close to the margins of reality (8)
TRICKERY : [ TRICE(an instant in time) containing(assuming) the last letter of(…’s close) “Nick” ] plus(to) the 1st and last letters of(the margins of) “reality“.
29 Poem referring to Nationalist leader is included in collection (6)
SONNET : [ ON(refering to) + the 1st letter of(… leader) “Nationalist” ] contained in(is included in) SET(a collection of things with something in common).
Down
2 The Comte d’Artois was one for a change of regime (6)
EMIGRE : Anagram of(a change of) REGIME.
Defn: What the Comte d’Artois or King Charles X of France was, twice, having gone into exile twice in his lifetime.
3 Record set by Border taking an age to get to fifty is short-lived (9)
EPHEMERAL : EP(a vinyl recording format, with more content than a single, but less than an LP) plus(set by) HEM(border;edge) plus(taking) ERA(an age;a long distinctive period of time) plus(to get to) L(Roman numeral for “fifty”).
4 Concerned with convert’s total change of opinion (5,4)
ABOUT TURN : ABOUT(concerned with) + TURN(to convert, as in “to turn water to ice” or even, “to turn a spy”.
5 Tory minister to argue earnestly (7)
CONTEND : CON(abbrev. for “Conser vatie” Party member;a Tory) + TEND(to minister to;to take care of).
6 Completion of service by bishop after protest (5)
DEMOB : B(abbrev. for “bishop” in chess notation) placed after(after) DEMO(short for demonstration;a protest).
Defn: … in the military.
7 Foolish to write about getting involved in it (5)
INEPT : Reversal of(… about) PEN(to write) contained in(getting involved in) IT.
8 Not exactly ethical to implicate new telephone service (8)
CHATLINE : Anagram of(Not exactly) ETHICAL containing(to implicate) N(abbrev. for “new”).
13 Timeless recording of mimic (3)
APE : T(abbrev. for “time”) deleted from(…less) “tape”(a recording on tape).
15 Cruel Nazi leader impounds the French paintings first (9)
HEARTLESS : HESS(Rudolf, Nazi leader) containing(impounds) [ LE(French for “the”) placed after(… first) ART(paintings) ].
16 Depressed after opening of explanatory analysis (9)
BREAKDOWN : DOWN(in a state of depression) placed after(after) BREAK(an opening;an opportunity, as in “a lucky break”).
17 Prepared to hedge in case rule about returning causes confusion (8)
DISORDER : DID(I guess if you did the preparatory steps, you’d be prepared) containing(to hedge) [ SO(in case;if, as in “so we miss the last bus, what will we do then?”) + R(abbrev. for “rule”) ] + reversal of(… returning) RE(about;with reference to).
19 Shakespeare taking the lid off evil (3)
ILL : “Will”(what you might familiarly call William Shakespeare) minus its 1st letter(taking the lid off).
20 Slight cut in the highest level of attainment (7)
SKETCHY : ETCH(to engrave;to cut into metal, glass or stone) contained in(in the) SKY(the highest level of attainment, as in “the sky’s the limit”).
Defn: …;with little substance or detail.
21 Intended to spread out around front of Italian church (6)
FIANCE : FAN(to spread out) containing(around) the 1st letter of(front of) “Italian” + CE(abbrev. for the Church of England).
Defn: …;betrothced.
23 King leaving thug in charge of ancient Carthage (5)
PUNIC : “k”(abbrev. for “king”, in chess notation) deleted from(leaving) “punk”(a thug) + IC(abbrev. for “in charge”).
24 Happen as a result of largely unseen wavering (5)
ENSUE : Anagram of(… wavering) “unseen” minus its last letter(largely …).
Very enjoyable and just the right level for a lazy Sunday morning. Thanks to setter and blogger.