Count-up timer

This count-up timer measures how long it has been since a start date and time you choose. The Start Date & Time field is a datetime-local input. Press Start and four cards show days, hours, minutes, and seconds elapsed, updating once per second. Stop freezes the cards. The start field is disabled while the timer is running so you cannot accidentally edit the origin mid-count.

The default start value is “now” when the page loaded, which makes the first run behave like a simple elapsed clock from this session. You can also pick a past birthday, launch, hire date, or project kickoff and Start — the cards then show the full span in days plus leftover hours, minutes, and seconds. If the start date is in the future, the cards stay at zero until that moment arrives (or they show the empty-state copy before you have started).

There is no Reset button on this page. To start over, press Stop, change the start date if you need a new origin, and press Start. There is no lap list and no hundredths. Those belong to the online stopwatch. There is also no remaining-time display; that is the countdown timer.

Like the other FlashKit clocks, this one is local to the tab. It does not write to localStorage, does not create a shareable “days since” page, and does not invoice billable hours. Copy the numbers if you need them in a timesheet or a chat. Closing the tab ends the session.

Use the count-up timer for multi-day or multi-hour spans. Use the stopwatch for short sessions with laps. Use the countdown when you care about time left until a deadline. Switching among the three is the intended internal path — they are siblings, not duplicate doorway pages.

How to Use

  1. Set Start Date & Time. Leave the default (now) to count from this moment, or pick a past timestamp to measure a longer span.
  2. Click Start. Days, hours, minutes, and seconds fill in and tick about once a second. The date field locks while the timer is active.
  3. Leave the tab visible if you are using the cards as a live display.
  4. Click Stop to pause. The start date becomes editable again.
  5. To begin a new span, change the start date if needed and click Start. There is no separate Reset control.

Key Features

  • Elapsed days, hours, minutes, and seconds from a start date
  • Start date locked while the timer is running
  • Start and Stop only — no lap list and no Reset button
  • Future start dates stay at zero instead of counting backwards
  • Runs in this tab; no FlashKit account or shared “days since” URL

When a count-up clock is the right tool

  • Days since a launch, release, or “sober since” date you want on a personal display — private, not a public counter widget.
  • How long a meeting, lab, or on-call shift has been running when you care about hours more than hundredths.
  • Project age: set the kickoff date once and Start. This is a clock, not a Gantt chart or invoice.
  • Classroom “time on task” on a shared screen, as long as someone is watching the tab.
  • Any span longer than a typical stopwatch session, where minutes overflowing past 59 would be harder to read.

Tips that match this UI

  • Change the start date only after Stop. The field is disabled on purpose while the timer is active.
  • A future start date is valid but stays at 00 days / 00 hours until that instant. It does not count down.
  • There is no Reset. Stop, edit the date, Start — that is the restart path.
  • Background tabs can lag the one-second interval. Keep the page in front for a kiosk-style display.
  • Need laps or hundredths? Use the online stopwatch. Need time remaining? Use the countdown timer.

Accessibility notes

  • Start Date & Time is a labeled native input. It becomes disabled (not removed) while the timer runs, which most assistive tech announces as unavailable.
  • Start/Stop is a native button. The four cards pair a large number with a text label so color is not the only cue.
  • Empty and future-start states use ordinary paragraph text (“Timer not started or start date is in the future.”), not a modal.
  • There is no aria-live ticker. The page will not speak each second. Zoom the cards if you are presenting them to a room.

Frequently Asked Questions

How is this different from the online stopwatch?

The stopwatch starts from zero, shows minutes:seconds.hundredths, and records laps. This count-up timer shows days, hours, minutes, and seconds from a start date you choose. It has no Lap or Reset button.

Can I use this as billable time tracking?

Only as a visible clock. There are no clients, invoices, exports, or locked timesheets. Copy the numbers yourself if you need them in another tool.

What if my start date is in the future?

After Start, the cards stay at zero until that timestamp. Before Start you may see the empty-state sentence. The tool does not count down to a future start — that is the countdown timer’s job.

Where is the Reset button?

There is not one. Press Stop, change the start date if you want a new origin, and press Start. Reset exists on the stopwatch, not here.

Does the elapsed time save in my browser?

No. It is not written to localStorage. Close or refresh the tab and you start over with a new default “now”.

Is the start date sent to FlashKit?

No. Elapsed-time math runs in this tab from your device clock. Nothing is uploaded for this tool.

Related Tools