Neptune's years are 164.8 Earth years. Its days are 16 hours and 6.7 minutes long. Although Neptune's days are shorter than our days, its years are still longer than ours.
Most colorants will last in your pond approximately 30 days. You may have to add more pond dye before 30 days if you have execissive rainfall, run-off, a heavy out flow, or evaporation. If your colorant is fading you will visually be able to tell and should add more dye to the water.
If your liner is vinyl we recommend that you drain the pond, make your repair using Boxer #500 or #700 based adhesive. Allow drying time of 2 days (in cooler weather 4-5 days). Boxer #100 adhesive based repair kits would work but complete drying time (for fish safety) would be prohibitive.