CruiseStar
Two different philosophies
Fixed-time dining assigns you one seating, an early slot around 5:30-6:00 p.m. or a late one around 8:00-8:30 p.m., with the same table, waitstaff, and often the same tablemates every night. Flexible dining, which shows up under names like My Time Dining, Anytime Dining, or Freestyle depending on the line, lets you walk into the main dining room whenever it suits you within its open hours, either as a reservation or a walk-in, without being locked to one time or table.
Which one actually fits you
Fixed dining rewards people who like routine, the same waiter learning how you take your coffee, a familiar table of company by night three. Flexible dining rewards people whose days don't run on a schedule: excursions that finish late, a show you want to catch right after dinner, or just not wanting to commit to one time for a full week. Neither is the "correct" choice; it really comes down to how much structure you want on vacation.
The trade-offs of going flexible
You won't automatically get the same waiter or table twice, though you can usually request a favorite if one night goes especially well. And while you can often walk right in outside peak hours, the busiest window, almost always right around 7:00 p.m., can mean a short wait without a reservation, which the cruise line's app makes easy enough to book around.
If you change your mind
Most lines let you switch from fixed to flexible (or vice versa) up until some cutoff before sailing, and sometimes even once onboard by talking to the dining team on embarkation day, though it's not guaranteed if the ship is already full in that style. Worth knowing too: specialty dining reservations are booked completely separately from whichever main dining style you choose, so mixing a fixed seating most nights with the occasional specialty dinner is entirely normal.
For families specifically
Flexible dining tends to work better with young, tired kids who can't hold out for a late seating, though an early fixed seating covers the same need if your family prefers a predictable dinnertime every night. Either way, it's less about which is objectively better for kids and more about which matches your family's actual rhythm.