Fibonacci numbers can be applied to anything...I personally haven't found FIB time lines advantageous to my way of trading...same goes with Gann's stuff. I suppose some trader's may find them useful.
My shortest "time frame" would be approximately 15 minutes of bars on a chart... I use Tick charts mainly - they minimise the affects of "time" in favor of activity levels... That said, the smallest increment I use is 30 ticks...meaning it takes 30 trades to complete one bar (for the YM, NQ and RUT e-minis) The ES e-mini is very much more active - my smallest interval is 120 ticks per bar.
I describe the differences in Tick and Time based charts in depth about half way down the page on my blog: Discretionary Trading ...TICK vs TIME charts (my blog page number 7) ...