THE NUMBERS, EXPLAINED
How to use this calculator.
Same-day time arithmetic using minutes after midnight. Recommended departure protects against earliest pickup; latest departure only meets the latest stated pickup.
Start with your inputs
Enter earliest pickup minute after midnight, latest pickup minute after midnight, walking time (min), required arrival buffer (min). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Earliest pickup minute after midnight | 480 |
| Latest pickup minute after midnight | 490 |
| Walking time (min) | 10 |
| Required arrival buffer (min) | 5 |
A worked example
With the example inputs above, departure for earliest pickup (minute of day) is 465. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Departure for earliest pickup (minute of day) | 465 |
| Departure for latest pickup (minute of day) | 475 |
| Pickup uncertainty window (min) | 10 |
How this is calculated
Departure for earliest pickup (minute of day)
Subtract walking time and buffer from earliest pickup.
Departure for latest pickup (minute of day)
Subtract walking time and buffer from latest pickup.
Pickup uncertainty window (min)
Subtract earliest pickup from latest pickup.
Symbols and units
- a
- Earliest pickup minute after midnight
- b
- Latest pickup minute after midnight
- c
- Walking time (min)
- d
- Required arrival buffer (min)
Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.
Assumptions and limits
Same-day time arithmetic using minutes after midnight. Recommended departure protects against earliest pickup; latest departure only meets the latest stated pickup.
Calculations use the values you enter. Blank or invalid inputs show an error instead of silently substituting zero. Results are displayed to useful precision; calculations retain the underlying numeric precision.
Questions about this tool
What does the result tell me?
Departure for earliest pickup (minute of day); Departure for latest pickup (minute of day); Pickup uncertainty window (min). The result applies to the method and inputs described above. Check the units and assumptions before using it in a decision.
Why might another calculator differ?
Differences in units, rounding, timing or model definitions can produce different answers. Compare the input definitions and the method, rather than only the final number. For this tool: Same-day time arithmetic using minutes after midnight. Recommended departure protects against earliest pickup; latest departure only meets the latest stated pickup.
Are my inputs stored or sent to AI?
Calculations on this page happen in your browser. The separate AI question finder sends its submitted conversation to OpenAI; these calculator fields are not sent. Favourites and recent tool names are stored locally. A shared link contains the inputs you choose to include.
Further reading
OpenStax: Solve proportions and their applications ↗
Background reading; this does not imply endorsement or independent review of SumFizz.
Review status
Software example and browser checks are recorded in our quality report. No external expert review is claimed. Created with coding assistance; calculations run as ordinary browser code.
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