Here's a quickie little guide I banged out (no guarantees as to accuracy) which shows you which events have competition on which days.

OLYMPIC TRIALS ROUNDS

(days 5 & 6 are rest days, no competition)

MEN
100—2, 2, 3, 3
200—8, 9, 9, 10
400—3, 4, 7
800—1, 2, 4
1500—7, 8, 10
Steeple—7, 9
5000—1, 4
10,000—8
110H—9, 9, 10, 10
400H—1, 2, 3
20W—9
HJ—7, 9
PV—1, 3
LJ—1, 3
TJ—8, 10
SP—1, 2
DT—7, 10
HT—4, 8
JT—8, 10
Dec—3, 4

WOMEN
100—1, 1, 2, 2
200—8, 9, 9, 10
400—3, 4, 7
800—1, 2, 4
1500—7, 8, 10
Steeple—4, 7
5000—4, 8
10,000—1
100H—9, 9, 10, 10
400H—1, 2, 3
20W—10
HJ—4, 8
PV—7, 10
LJ—4, 7
TJ—1, 3
SP—7, 9
DT—1, 3
HT—7, 9
JT—2, 4
Hept—1, 2