Cuerun field notes

A running order you can read.

A small event often starts as a list: an introduction, a demonstration, questions, a break and a final session. Turning that list into clock times means adding durations repeatedly. A late change near the top can leave several later times wrong. Cuerun keeps one ordered sequence and recalculates every boundary when you edit or move a segment.

The result is a planning sheet for a rehearsal, workshop, presentation evening or another sequence where one item follows the last. It does not send reminders or watch an event while it runs. The durations are the values you entered, so the report records that particular version of your plan.

A clock is a position; a duration is an amount

The start uses a plain 24-hour clock: 19:30 or 19:30:00. Hours run from 00 to 23; minutes and seconds run from 00 to 59. Enter 07:00 with two hour digits for seven in the morning. This whole-second form is a narrower choice within the WHATWG plain-time syntax, with no date or timezone.

Two duration fields mean minutes:seconds. Thus 45:00 is 45 minutes and 1:00 is one minute. Three fields mean hours:minutes:seconds: 1:00:00 is one hour. A duration can exceed a clock hour or a full day. For example, 60:00 and 1:00:00 both represent 3,600 seconds.

Use whole seconds, digits and colons. Seconds have two digits after the last colon. In three-field form, middle minutes also have two digits and stay below 60. The parser ignores outer spaces and rejects extra characters inside a value. It is not a general ISO duration parser and accepts no written units, fractional seconds or timezone suffixes.

What the calculation adds

Each row becomes an integer number of seconds. Its start is the original start clock plus the durations before it; its end includes its own duration. Cuerun keeps elapsed time separately from the wrapped clock. There is no gap unless you enter one as a row.

To display a clock, the whole count of 86,400-second blocks becomes a relative day offset. Remaining seconds become that day's clock. These unit relationships appear in Table 8 of the BIPM SI Brochure. A fixed day unit here is a planning convention, not a statement about a particular timezone-aware civil date.

Example: a two-hour workshop

Moving the session before the break changes intermediate cues while preserving total duration. Removing a row removes exactly its entered duration from later cues. A newly added row asks for its duration before another valid sheet is displayed.

Example: midnight, then another day

Start at 23:59:30 and enter 0:45. That means 45 seconds. It ends on Day +1 at 00:00:15, even though only 0:00:45 has elapsed. Subtracting the visible clock strings would lose the wrap, so the report retains elapsed second counts.

Append 24:00:00. That second item starts on Day +1 at 00:00:15 and ends on Day +2 at the same clock. Total elapsed time is 24:00:45, or 86,445 seconds. Keep day offsets with a shared report: a clock label alone cannot tell a reader which boundary it describes.

An intentional zero is a milestone

A row entered as 0:00 starts and ends at the same planning time and is labeled a milestone. It can mark a handover or cue without adding elapsed time. An empty duration is an unfinished entry, not a zero; it prevents calculation. If an announcement itself takes time, give it a nonzero duration.

For example, start at 08:00 with a 0:00 marker and a 10:00 activity. The marker is at 08:00 and the activity runs from 08:00 to 08:10. Neither an automatic pause nor a guessed allowance is inserted.

Make practical breaks visible

A named five-minute changeover appears in the result, while a gap kept only in your head is absent. Use labels that help someone reading the sheet: “Questions,” “Room change” or “Short break” can be clearer than an unexplained interval.

This model does not know that a later item has a fixed appointment. It keeps entries contiguous and shifts later times when an earlier duration changes. Parallel rooms, overlaps and fixed-time constraints need a broader coordination plan. One contiguous list does not solve those constraints.

Relative days are not dates

Day 0 is the starting clock day. Day +1 means the sequence crossed its first midnight boundary on this plain planning clock. There is no location, date or daylight-saving rule. Leap seconds are excluded; 23:59:60 is invalid.

The WHATWG duration definition separates fixed second amounts from months and years, whose lengths depend on the calendar. This calculator accepts neither months nor years. Use a date- and timezone-aware system when an actual clock change or cross-location appointment matters.

A report that describes the current input

Text and CSV files are created locally from the current valid result. The text report retains every label, boundary, day offset and elapsed amount. CSV includes numeric seconds alongside readable times. Formula-like labels are escaped only in the CSV file; the screen still displays your original text.

If the browser refuses clipboard access, a local text box supplies the same report for manual copying. A pending copy cannot restore feedback after an edit or reset. Invalid input clears the old schedule and disables every export, so an older answer cannot appear to describe edited values.

Up to 120 rows and 168 total hours are supported. Those are software limits, not suggestions for event length. Entries are not saved to storage or an account. Keep a report before leaving when you need a record, and reset the example for a clear starting point.