Timeline generator, history and project schedules drawn to scale and checked for errors
A timeline turns chronology into physical distance, so a hundred years actually takes up a hundred times more space than one year. Load the Bulgarian or the world preset, or enter your own events, pick a linear or logarithmic scale, and the tool checks for year zero errors and overlapping reigns before it lays out a printable A4 or A3 file. A separate project mode does the same job for a schedule, with a critical path and a resource histogram.
Open the timeline generator A free account opens this tool. The interface is in English and nothing you enter leaves your browser.How it works
Three steps for a history timeline, with project scheduling and other modes alongside it.
Load a preset or enter your events
Start from the 27 event Bulgarian preset, from the 681 treaty with Byzantium to EU accession in 2007, or the 29 event world preset spanning over 5000 years from the unification of Egypt, or enter your own events with a year, a category and a label. Each year is converted internally to an astronomical year, so a year 0 in your input is rejected with an explanation, since no historical calendar has one.
Pick linear or logarithmic scale and the paper size
Linear scale is geometrically correct but a timeline spanning thousands of years becomes unreadably long or crushes recent centuries into a few millimetres. Logarithmic scale compresses the distant past so every event stays visible, at the cost of distance no longer being proportional to years. Choose A4 or A3, portrait or landscape, and the tool works out the exact sheet count.
Check the warnings, then print or export
The tool flags any event outside your chosen period, any year 0 entry, and any two events in the same category whose reigns or durations overlap, such as two rulers governing at the same time during a fragmented period. Warnings do not block the output, since overlapping reigns can be historically real, but they tell you exactly which two events to double check.
Nine modes sharing one date engine
History, geology and project scheduling read from the same astronomical year and Julian day arithmetic.
Built to catch the errors chronology actually produces
Most timeline mistakes are not about drawing the line, they are about a calendar that skips year zero, a century that does not start where it feels like it should, or a sum of task durations that quietly assumes nothing runs in parallel.
Astronomical year numbering fixes the year zero problem
The calendar has no year 0, jumping straight from 1 BC to 1 AD, which makes naive subtraction wrong: the gap from 2 BC to 2 AD is three years, not zero. The tool converts every year to a continuous astronomical year, where 1 BC becomes 0 and 100 BC becomes minus 99, so distances between events on either side of the BC/AD boundary come out correct without the teacher having to do the conversion by hand.
Overlapping reigns flagged, not silenced or blocked
When two events in the same category, most often rulers, cover overlapping years, the tool shows a warning naming both events rather than either rejecting the input or ignoring the overlap. Ivan Shishman in Tarnovo and Ivan Sratsimir in Vidin genuinely ruled at the same time during the country's fragmentation, so the check has to allow a real historical overlap while still catching a typo.
Critical path with a cycle check before it runs
The critical path method sorts the task network topologically, using Kahn's algorithm, before running the forward and backward passes that find early and late starts. That catches a circular dependency, task A waiting on B waiting on A, immediately with a clear error, instead of letting the forward pass hang while trying to resolve a network that can never settle.
What each mode leaves out, stated directly
PERT beta and Monte Carlo simulation compute two different averages from the same three estimates and are not interchangeable. The Monte Carlo simulation, the erosion model and the fractal terrain generator all run a capped number of iterations or precomputed frames on the main thread rather than a Web Worker, so a large run shows a visible calculating state rather than freezing silently.
Frequently asked questions
Why is there no year 0 and why does that matter?
The calendar moves directly from 1 BC to 1 AD with no year 0 between them, so subtracting years across that boundary the ordinary way gives a wrong answer: 2 BC to 2 AD is three years apart, not four minus two. The tool solves this by converting every year to a continuous astronomical year internally, and rejects any input of year 0 BC or AD with an explanation, since that year never existed.
Why is the 21st century 2001 to 2100 and not 2000 to 2099?
Century N covers the years ending ...01 through ...N00, so the 20th century is 1901 to 2000 and the 21st is 2001 to 2100. Someone living in 2000 is still in the 20th century, a common source of confusion the tool does not paper over. For BC years the direction of counting reverses, since a larger BC number is further in the past.
When should I use a logarithmic scale instead of linear?
A linear timeline from the unification of Egypt around 3100 BC to the present, over 5100 years, would need a strip more than ten metres long at a normal scale, and recent centuries would be crushed into a few unreadable millimetres. A logarithmic scale compresses the distant past so every event stays visible, at the cost that distance along the strip is no longer proportional to the number of years, which the tool states plainly rather than disguising.
What is the difference between PERT and Monte Carlo averages for a project task?
Given an optimistic, most likely and pessimistic duration, the PERT beta formula weights the most likely estimate four times and divides by six. The triangular distribution actually sampled by the Monte Carlo simulation has a plain arithmetic mean of the same three numbers divided by three. For estimates of 2, 4 and 12 days these give 5.00 and 6.00 respectively, two different numbers, not a rounding difference between the same one.
Does the critical path just add up every task's duration?
No, and assuming so is the most common project planning mistake. If two tasks run in parallel, with nothing forcing them to happen one after another, total duration follows the longer of the two branches, not their sum. The critical path is the chain of tasks with zero float, where any delay pushes the whole project back, and tasks off that path have float, meaning they can slip without moving the deadline.
What does the timeline tool not check for me?
It verifies the formal chronology, meaning the period bounds, year 0, and overlapping entries, but it does not verify that a date is historically accurate. A handful of ancient dates, the unification of Egypt, the founding of Rome, the first Olympic Games, are traditional dates by the historiography's own account, not laboratory proven, and are shown exactly as given so the teacher can check them against the textbook before printing.
Other tools
Part of the EduFacturing tool set for education and project planning.
The rest of the tool set
A free account opens the full set: timelines, relief maps, tolerances, printability checks and the rest.
Create a free accountFree account. No card, no trial period.