Chronos Help Documentation

A complete guide to Chronos, from your first task to a week of insights.

Last Updated: November 12, 2026

1. Getting Started

Above the tool are the five views: Today, Week, Tasks, Focus and Insights, then Settings and How it works. Under them, the now bar shows what is on at the moment, and it stays under the site's header while you scroll. Chronos opens on Today. The round button at the top right switches the site between light and dark.

The quickest start: type a few lines in the box on Today, such as "Write the report 90m #work !!" or "Gym 7am 1h every mon wed fri #health", then press Plan my day. When nothing is planned yet, the waiting list offers four example lines to try.

2. The Quick-Add Box

Type a title and any details in plain words; the line under the box shows what will be made (a new task, block or routine) and how each detail was read. Press Enter or Add.

• Time: 10am, 9:30, 14:00, 9.30 pm, noon, midnight, at 6 (a bare "at" from 1 to 6 means the evening). A range: 10-11:30, 9am to 5pm, from 14:00 until 15:30.
• Length: 45m, 90 min, 1h, 1.5h, 1h30, 1 hr 15 min, for 2 hours, half an hour, an hour, a quarter of an hour.
• Day: today, tonight, tomorrow, day after tomorrow, friday (the coming one, today included), next friday (in the following week), in 3 days, in 2 weeks, next week, 25 oct, oct 25, the 3rd of may, 25/10 (day first or month first, as set in Settings) and 2026-11-20.
• Category: #work, #health, or the start of any category name. Priority: !, !! or !!! (low, medium, high), or !low, !medium, !high. Due: by friday, due 1 nov, before tomorrow, deadline 30/11.
• Repeat: every day, daily, every weekday, every weekend, every mon, every mon wed fri, every tue and thu.

A line with a repeat becomes a routine (at 9:00 for 30 minutes when no time or length is given); a line with a time becomes a block (an hour when no length is given) on the day shown, or on the day typed; anything else waits as a task (30 minutes when no length is given). A block typed with a priority or a due date also gets a task behind it.

3. Today: the Timeline

The day's timeline has two lanes: Plan on the left and Done on the right. It runs from the start to the end of your day, as set in Settings, and stretches to show anything outside those hours. It scrolls inside its own box, which opens with the current time a third of the way down; the past is shaded a little, a line marks now, and free stretches of half an hour or more are labelled. The arrows next to the date, Pick a day and Back to today change the day.

• Drag down the Plan lane to draw a block, or click to add a one-hour block at that time. On the Done lane, the same adds time you already spent.
• Drag a block to move it, and its bottom edge to change its length. On a touch screen, press and hold first. Esc cancels a drag.
• The round tick at a block's top right marks it done. Click a block to open it.
• Taller hours and Shorter hours change the scale (three sizes).

4. The Dial and the Day's Totals

The dial shows the day as a 24-hour clock with noon at the top. The outer ring is the plan, the inner ring is what was done, the hours outside your day are shaded and a hand points at now. Point at an arc to see what it is and click it to open it. In the middle, today shows the clock and what is on now, the next block or the running focus round or timer; another day shows its weekday and its totals.

Under the dial, a line sums up the day: planned and done time and the free time left before the day ends (for a past day, how many planned blocks got done and their share of the planned time). The category list shows done against planned time for each category.

5. Waiting Tasks and Plan My Day

Waiting to be placed lists the tasks that have no time yet and are not done, most pressing first. Drag one onto the Plan lane, press Place to put it in the next free time on that day, or click its title to open it. On a phone the first four are shown, with Show all for the rest.

Plan my day fits every waiting task into the free time of the day shown (today from now on), and shows the result before anything changes:

• Order: past their due date, due that day, planned for that day, then by priority, due date and length (longer first).
• Tasks of an hour or more, or marked as needing deep focus, go into your best hours; the rest into the earliest free time that fits.
• The hours are your work hours on work days and your day hours on other days; change them in the window for that plan.
• The gap (none, 5, 10 or 15 minutes) is kept before and after each block it places and around the blocks already there.
• A task of an hour or more that fits in no single free stretch is split into parts of at least half an hour, when all of them fit. Tasks that still do not fit stay waiting.

Press Place them to put the blocks on the day; Undo takes them all back. On today you can choose Plan tomorrow instead.

6. Blocks and Tasks in Detail

A block has a name, a day, a start and end time (type 9, 930, 9:30, 2.15pm or noon; the chips set a length), a category, notes, and optionally a task it is part of. Pick days under Repeat every week on to turn it into a routine. An open block also has a Done switch and, on today, Track it.

A task has a name, a category, a length, a priority, a day to do it on (it waits at the top of that day), a due date, a Needs deep focus switch, steps with ticks (up to 50) and notes. Under Urgent and important you can set both by hand instead of letting Chronos work them out. An open task shows when it is planned and how much time was tracked for it; Track it, Place it and Delete are at the bottom. Renaming a task renames its blocks that are not over yet.

Ticking a task done takes its later blocks off the plan; Undo puts them back. Deleting a task keeps its blocks as plain blocks.

7. Week, Routines and Goals

Week shows seven days side by side in a box that scrolls, starting on the day set in Settings; work days are unshaded and today is tinted. Each day's head shows its planned time and a bar of what was done; click it to open the day. A strip at the right edge of each day shows the time tracked. Drag a block to another day or time, or draw a new one. The arrows change the week.

Routines lists every routine with its days, time and category. Pause stops it showing on your days; the pencil opens it. A routine has days of the week, a time, a category, and a start and an end date. On one day, a routine block can be moved, resized, ticked or skipped without touching the other days; choosing Every day it repeats in the block changes them all.

Hours by category sums the week's planned and done hours per category. Give any category a weekly goal from 1 to 50 hours; its mark shows on the bar and the line under it says how far you are from it.

8. Tasks: List and Urgent and Important

Tasks lists everything to do in groups: past the due date, today, tomorrow, the next 7 days, later and no date. Search looks through titles and notes, the chips show one category, and Show done adds the tasks finished in the last 30 days. Each row has a tick, the details, Place (for a waiting task) and a button to start tracking it.

Urgent and important sorts the same tasks into four boxes: do first, give it a time, keep it short, and later or drop it. A task counts as urgent when it is due within two days and as important when its priority is medium or high, unless you set either by hand; drag a task to another box to set both.

9. The Now Bar and the Timer

The bar under the tabs shows the block on now with Track it, Focus and Done; between blocks, the free time until the next one with Start a timer; the running timer with Change and Stop; or the focus round with its buttons. While a timer or a round runs, the browser tab shows its time.

A timer can start from the bar, from a task, from a block or from a reminder; Started at lets you begin it earlier than now. Stop adds the time to the Done lane (less than a minute is not kept); Throw away drops it, with Undo. Starting a timer stops a running focus round or another timer, and a stretch of tracked time is at most 31 days.

10. Focus Rounds

On Focus, pick a rhythm: 25 and 5 (a 15-minute long break after 4 rounds), 50 and 10 (20 after 3), 90 and 20 (30 after 2), 52 and 17 (30 after 3) or Your own (10 to 120 minutes of focus, breaks of 1 to 20 and 10 to 45 minutes, a long break after 2 to 6 rounds). Choose what you are working on, a block on today's plan or a waiting task, and press Start.

• The ring fills as the round goes; the dots show the rounds before the long break. Pause, Skip and Stop sit under it, and Space starts or pauses a round.
• Start breaks by themselves and Start the next round by itself decide whether the next phase starts on its own. Count focus time as done on the day adds each worked stretch to the Done lane.
• A break shows a small idea for the break, such as standing up or looking at something about 6 metres away for 20 seconds.
• If a round or break ends while the computer sleeps and it is found more than ten minutes late, the next phase waits for you instead of starting by itself, so no time is counted for hours nobody worked.
• Something came up? Type it in the note box and press Note it: it becomes a waiting task, listed under Noted during focus.

Today lists the rounds of the day with their times, the full ones and those cut short, and the days in a row with at least one round.

11. Ending the Day

End the day (on today or an earlier day) shows planned and done time, the planned blocks that got done and the time per category. Each unfinished task (planned that day, due by then or with a block that day) gets a choice: tomorrow (the default), back to waiting, it is done or drop it. Say how the day felt, from Drained to Great, and write a line for yourself. Close the day saves it; the toast offers to show tomorrow.

12. Insights

Choose this week, the last 7 days, the last 30 days or this month. The line at the top gives the tracked time and its daily average, and how many planned blocks that are over got done.

• Planned and done, day by day: bars for each day, or a table with Show as a table.
• Where your time went: done time per category, with a mark for the planned time.
• When you get things done: a heat map of tracked time by weekday and hour within your day hours, with the three hours you track the most.
• Your estimates: for tasks finished in these days with a length and at least 5 minutes tracked, the middle value of tracked time divided by the planned length, and the last eight tasks.
• Focus and how the days felt: full rounds, focus minutes, the current streak and the feeling of each rated day, with the tracked time on good and low days when there are both.
• Tracked time: every stretch in these days, newest first (up to 300), to open and change; Add time and Spreadsheet file (a CSV of all tracked time) sit above it.

13. Calendar Files

Press Calendar file on Week (or in Settings).

• Save the file writes this week, the next 4 weeks or the day shown as an .ics calendar file. Blocks become events with their notes and category; routines become weekly repeating events with their end date, skipped days and moved days. Blocks that came from a calendar file are left out, so they do not appear twice in that calendar.
• Pick a calendar file reads an .ics file exported from Google Calendar, Outlook, Apple Calendar or another calendar, on your device. Timed events from a week ago to two months ahead come in as blocks in the category you choose, at your clock's time. Each event follows its own time zone; daily and weekly repeats come in with their interval, count, end, skipped days and moved or cancelled single events. All-day events and monthly or yearly repeats are left out, events already brought in are not added twice, and at most 2,000 come in at a time. The window says how many were found, left out or could not be read.

14. Reminders and Notifications

In Settings, choose when to be reminded before a planned block: never, when it starts, or 5, 10 or 15 minutes before (5 at first). A reminder shows a message in the page with Track it, and plays a soft bell if the bell is on. Show notifications when Chronos is in the background asks the browser for permission; then reminders and the end of focus rounds also show as notifications while the tab is open but out of sight. A closed tab cannot remind you. A reminder found late, when the computer slept, is shown up to two minutes late for "before" and ten minutes late for "now", then let go.

15. Settings and Categories

• Your day: when the day starts and ends (the timeline's hours and the dial's shading) and your work hours and work days (used by Plan my day).
• Clock and calendar: a 24-hour or 12-hour clock, the week starting on Monday or Sunday, and whether 5/10 means 5 October or May 10. They follow your device the first time.
• Planning: times snap to 5, 10, 15 or 30 minutes; the gap between planned blocks; your best hours for deep work.
• Reminders: as above, with the bell and notifications.
• Categories: rename them, give each one of eight colours or grey, add up to 12 in all or delete one (its items move to Other, with Undo). Other is always kept.
• Your data: Save a backup, Restore a backup (checked value by value, with Undo), Calendar file, Spreadsheet of tracked time and Delete everything (after you type DELETE).

16. Keyboard and Accessibility

• N adds something (the quick-add box), T goes to today or this week, J and K go to the day or week before and after, 1 to 5 switch views, Space starts or pauses a focus round on Focus, ? opens the help and Esc closes a window.
• On a chosen block: the up and down arrows move it, Shift with them changes its length, left and right move it to another day on Week, Enter opens it and Delete removes it (with Undo).
• The keys work while the tool is in use, not while you type in a box or a window is open. The arrow keys, Home and End move between the views when one is focused.
• Tab reaches every button, box and block; the timeline boxes can be scrolled with the keyboard. Blocks are named with their time, category and state for screen readers, the planned and done chart has a table view, and changes such as a moved block are announced.
• With reduced motion turned on in your device, nothing slides or pulses.

17. Privacy and Your Data

Your tasks, blocks, routines, tracked time, focus rounds, reviews and settings are kept in this browser under one entry for this tool and never sent to a server; nothing is saved on a first visit until you add or change something. Data from the earlier Chronos app in this browser is brought over once. Calendar files and backups are read and written on your device. Chronos keeps up to 2,000 tasks, 5,000 blocks, 100 routines, 12 categories, 5,000 focus rounds, 1,000 day reviews and the newest 10,000 stretches of tracked time, and opens files up to 5 MB. Like every page on ZeroDataUpload, this page shows ads; the Privacy Policy explains them.

18. How It Was Checked

Before this page was published, the engine behind the tool was checked against references written from the rules on this page: 78,779 cases in 16 groups, run in several time zones, including ones where the clocks change. They include typed times and lengths, thousands of quick-add lines, days and clock times on the days the clocks change, blocks side by side, free time, thousands of days planned by Plan my day (no overlaps, the gap on both sides, the snap, the order), tracked time on each day, the sums behind Insights, the timer, focus rounds with pauses, skips and a computer that sleeps, reminder moments, calendar files written and read against the calendar standard and a separate calendar library, the spreadsheet file, and thousands of saved states, most of them made to break the tool. Then the page was tried at four screen widths in both themes.

19. Troubleshooting

• My planner is gone. It is kept per browser and device; a private window or cleared browser data starts afresh. Save a backup now and then.
• Plan my day says nothing fits. Widen the hours in its window, shorten the gap, move a block, or plan tomorrow. Today's planning starts from now.
• A typed line was read wrongly. Look at the words under the box before pressing Add; put the time and day after the title, or open the block afterwards and change it.
• No reminder came. Check Remind me in Settings and keep the tab open; for notifications in the background, allow them for this site in the browser.
• Some calendar events did not come in. Only timed events from a week ago to two months ahead are read; all-day events and monthly or yearly repeats are left out.
• A message says the browser has no room left. The browser's room for saved data is shared by the whole site. Save a backup, then clear other saved data in the browser.

20. Support

For questions the FAQ does not answer, use the contact form.