Drop-Frame Timecode
Drop-frame timecode is a counting scheme that keeps 29.97 fps material aligned with real elapsed time.
What this is about
Because NTSC-derived video runs at 29.97 frames per second rather than an even 30, a straight count drifts about 3.6 seconds per hour against the clock. Drop-frame compensates by skipping two timecode numbers each minute, except every tenth minute. No frames are ever deleted — only labels are skipped. Broadcasters working in 29.97 usually demand drop-frame so programme durations are true. Crews shooting 24, 25, or 50 fps never touch it, which is why it mostly appears in NTSC-market deliveries.
A term only helps when everyone on set means the same thing by it — so what follows is how it is used, not a dictionary definition.
What runs differently here
Where this differs from the general case:
- Frames are never dropped — only timecode labels are skipped
- Relevant only for 29.97/59.94 fps material and NTSC-market deliveries
- Semicolons in the display conventionally mark drop-frame counting
With TillyGen
When a delivery for an NTSC market sits in the plan, TillyGen keeps that spec visible early, so timecode format is set before the first card is recorded.
Change one constraint and the consequences travel through the whole plan: affected shots are flagged, the call sheet is regenerated, and nobody keeps working from yesterday's version.
Frequently asked
Does drop-frame throw away picture information?
No. It skips numbers in the counting, the way some buildings skip a floor label. Every frame that was recorded stays exactly where it is.
How long does it take to get started with TillyGen?
A first project takes under an hour to set up. There is no configuration phase in which templates and fields have to be defined before the tool produces anything.
Can the results be exported?
Yes — as PDF for the crew, CSV for downstream systems and through the API for anything automated. The plan stays the source; the exports are views of it.