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SLA Deadline Calculator

Calculate an SLA deadline from a start date and time plus duration in hours, calendar days, or business days. Optionally move a weekend deadline to the next business day.

SLA duration type

Weekend handling on deadline date

SLA deadline

Example

Saturday, August 16, 2025 at 9:00:00 AM UTC

2025-08-16 · UTC date

Based on

Started
2025-08-15 09:00 UTC
SLA duration
24 hours
Weekend handling
Included on deadline date
Weekend status
Deadline falls on a weekend

Next step: Business Day Offset Calculator

When to use this calculator

Use this calculator whenever a support, vendor, or internal service level agreement defines a response or resolution deadline as a duration from a start event—ticket creation, assignment, or acknowledgment.

  • Support ticket response SLA

    Find the exact deadline for a first-response or resolution target measured in hours from when a ticket was opened.

  • Vendor SLA compliance

    Check whether a vendor's response time is within a contracted SLA window before escalating.

  • Helpdesk breach monitoring

    Compute deadlines for a queue of tickets to flag which are approaching or past their SLA target.

  • Internal handoff SLAs

    Confirm the deadline for a business-day handoff between teams, such as finance to procurement.

Inputs

  • Start date and time (UTC)

    The date and time the SLA clock starts—when the ticket was opened, assigned, or acknowledged, as defined by your agreement.

  • SLA duration type

    Whether the duration is measured in hours, calendar days, or business days.

  • Duration

    The numeric length of the SLA window in the chosen unit.

  • Weekend handling on deadline date

    Whether to include weekends in the deadline as computed, or move a Saturday or Sunday deadline to the following Monday.

How the calculation works

All times use the UTC clock. Enter a start date and time, choose how long the SLA runs (hours, calendar days, or business days), then read the deadline instant.

Calendar days add whole days on the civil calendar and keep your start time. Business days skip weekends and can optionally skip a sample US federal holiday list. Hours add exact clock time from the start instant.

Weekend handling applies to the deadline's calendar date: include weekends keeps the computed instant; exclude weekends moves a Saturday or Sunday deadline to the following Monday (UTC), preserving the time of day.

Worked example

Start: Friday 5:00 PM UTC. Duration: 48 hours.

Deadline: Sunday 5:00 PM UTC (48 hours added directly to the start instant).

With weekend exclusion enabled, since the deadline falls on Sunday, the adjusted deadline moves to Monday 5:00 PM UTC.

For a five-business-day resolution SLA starting Monday 9:00 AM UTC instead, the deadline is the following Monday at 9:00 AM UTC—weekends are skipped during the count, not adjusted afterward.

Edge cases

  • Hour-based SLA crossing a weekend

    Hour mode adds continuous clock time regardless of weekends—a 48-hour SLA started Friday afternoon runs through the weekend unless the agreement explicitly pauses the clock outside business hours, which this calculator does not model.

  • Business-day SLA vs business-hour SLA

    This calculator's business-day mode counts whole weekdays, not business hours within a day. A "respond within 4 business hours" SLA needs hour mode with a start time that reflects when business hours begin, not business-day mode.

  • Deadline exactly at midnight UTC

    A deadline instant that lands exactly at 00:00 UTC on a weekend day is still evaluated by calendar date for weekend adjustment, even though the time itself is at the boundary between two days.

  • Zero-duration SLA

    A duration of 0 returns the start instant itself as the deadline—useful as a baseline check before entering a real SLA window.

Related Contracts & Legal Calculators

The Contract End Date Guide is the primary reference for how contract end dates are calculated, how they differ from notice periods, and which calculator to use for each step.

The SLA Deadline Guide covers response and resolution SLA deadlines, business-day vs hour-based clocks, and holiday handling for helpdesk and vendor agreements.

The Contract End Date Calculator projects a contract end date from a start date and term length, with 30-, 60-, and 90-day renewal reminder dates.

The Contract Expiry Calculator is the same date math, framed for the 'expiry date' language some contracts, licenses, and subscriptions use instead of 'end date.'

The Contract Duration Calculator works the other way: given a contract's start and end dates, it finds the exact term length in years, months, and days.

The Contract Renewal Calculator works backward from a known end date and a renewal or cancellation notice period, to find the deadline to act before auto-renewal.

The License Renewal Calculator and Certification Renewal Calculator apply the same issue-date-plus-validity-period math to licenses, permits, and professional credentials rather than contracts.

The SLA Deadline Calculator adds hours, calendar days, or business days to a start date and time to produce a response or resolution deadline in UTC.

For notice periods tied to an employment relationship rather than a contract or vendor agreement, see the Notice Period Calculator in HR & Employment.

For business-day counting that contract and SLA deadlines depend on, see the Business Days Calculator and Add Business Days To Date Calculator in Date & Business Days.

FAQ

Does this use my local time zone?
No. Inputs are combined as UTC. Convert externally if your SLA is tied to a specific region.
What is the difference between calendar days and business days?
Calendar days count every day on the calendar. Business days advance only on weekdays (Monday–Friday UTC) and can exclude listed US holidays when that option is enabled.
Can I calculate a business-hours SLA, not just business days?
Not directly—this calculator's business-day mode counts whole days, not hours within a business day. For an hours-based target, use hour mode with a start time aligned to your support hours.
How do I know if a ticket has breached its SLA?
Compute the deadline for the ticket's start time and duration, then compare it against the current time or resolution time. This calculator computes the deadline only—it does not track live ticket status.
Is this legal or contractual advice?
No. SLAs vary by vendor and contract. Use this for planning and confirm deadlines in your agreement.

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