Here are day-by-day highlights of the folklife festival. Call 357-2700 for details. FRIDAY -- All-day demonstrations by herbalists and pharmaceutical glass-blowers from New Jersey; French-Canadian Music of New England at noon; aviation pioneers share some flight lore at 2; New Jersey music at the Sylvan Theater at 7. SATURDAY -- All-day demonstrations by boat builders and lobster-trap makers from New Jersey; demonstration of cockpit procedures at 11, 1 and 3; old-time Creole music at 2:30; dance concert at the New Jersey stage at 5:30; ceremony and concert at 8 at the Departmental Auditorium (Constitution Avenue NW between 12th & 14th streets). SUNDAY -- Silk-process workshop from New Jersey at noon; French fiddle styles at 1; pullman porters and flight attendants talk about their jobs at 2; dance concert on the National Heritage stage at 5:30. MONDAY -- All-day restoration of the Wiseman-Cooke biplane; music of the Pine Barrens at noon; French-American craft demonstration at 3. THURSDAY, JUNE 30 -- Women in aviation at noon; Mardi Gras celebration at 2:30; swing music from New Jersey at 4. FRIDAY, JULY 1 -- All-day presentation of pilots' scrapbooks, logbooks in Pilots' Corner; dance workshop from Brittany at 1; labor history workshop from the New Jersey silk industry at 3; festival sampler concert at the Sylvan Theater at 7. SATURDAY, JULY 2 -- All-day boat building in the French- American craft tent; A Cappella Quintet from New Jersey at noon; concert of French and French-American music at the Sylvan Theater at 7. SUNDAY, JULY 3 -- French-influenced Mitchif Indian music at 2:30; Hispanic music from New Jersey at 4; New Jersey music at the Sylvan Theater at 7. MONDAY, JULY 4 -- Flight attendants' safety demonstrations at 11, 1 and 3; bon festival celebration from New Jersey at 1; French-inspired storytelling at 3:30.