How long does it take for 24% nitrogen fertilizer to show results?

Lawn I assume - with adequate rain/irrigation and warm weather should show results in a week or 2. Been a tad cool lately for late April. Some % of the N in lawn fertilizer is rapid release, usually ammonium sulfate and quickly available to the lawn grass if watered in; the remainder slower, time released N, often sulfur coated urea or polymer coated urea.

i laid down some 30-0-0 today on my bermuda, praying for some light rain tonight or tommorrow.

perfect timing, 1-1/4" rain in downtown chackbay yesterday. should see greening results next week...