How Due Dates Are Calculated

Route Simplified calculates due dates dynamically based on each generator's capacity, fill rate, and service history. Understanding this helps you know when to trust the system and when to intervene.

The two formulas

Current Fill Level = Gallons left at last service + (Fill Rate ÷ 30.4) × Days since last service

Days to due = (Capacity × Threshold % − Current Fill Level) × 30.4 ÷ Fill Rate

The threshold percentage is the fill level at which the system considers a tank due. Your administrator can view or adjust this in Settings.

Example

A 250-gallon tank with a fill rate of 100 gallons/month. The driver pumped it dry on April 1. Today is May 15 — 44 days later.

• Estimated fill: (100 ÷ 30.4) × 44 ≈ 145 gallons
• "Full" threshold at 95%: 250 × 0.95 ≈ 237 gallons
• Days to due: (237 − 145) × 30.4 ÷ 100 ≈ 28 days
• Due date: June 12

Two key takeaways

• The last service date is the anchor. If it's recorded incorrectly, every downstream calculation is wrong. Always verify the last service date when a due date looks suspicious.
• Fill rate is the lever. Adjusting the fill rate shifts all future due dates. Increase it to schedule sooner; decrease it to push dates out.

Manual overrides

You can enter a due date by hand on any Fill Rate generator. That override applies to the next service only. Once that service completes, the system resumes its fill-rate calculation with the new data folded in. Use manual overrides for one-off corrections — not as a substitute for fixing the underlying capacity or fill rate.