Workday

What Is a Workday in California?

In California, a "workday" is a consecutive 24-hour period that begins at the same time each calendar day. This legal definition is crucial for calculating daily overtime, determining meal break timing, and tracking hours worked for compliance purposes.

Unlike a simple calendar day, the California workday:

• Can start at any time the employer designates
• Runs for exactly 24 consecutive hours
• Resets at the same time every day
• Must be consistently applied

The default workday runs from midnight to midnight, but employers may establish a different workday start time based on their operational needs.

Why the Workday Definition Matters

California's daily overtime rules depend entirely on the workday definition:

Hours in a Workday	Pay Rate
Hours 1-8	Regular rate
Hours 8.01-12	1.5x (overtime)
Hours 12.01+	2x (double time)

The workday determines which 24-hour period these hours fall into. This matters significantly for:

• Overnight shifts
• Employees working across multiple days
• Shifts that span midnight
• On-call workers

California Labor Code Definition

California Labor Code Section 500(a) defines the workday:

"'Workday' and 'day' mean any consecutive 24-hour period commencing at the same time each calendar day."

Key Elements

Element	Meaning
Consecutive	No breaks in the 24-hour period
24-hour	Exactly 24 hours, not more or less
Commencing at same time	Must start at consistent time daily
Each calendar day	Applies every day, not just work days

Establishing the Workday

Employer's Right to Set the Workday

Employers have the authority to establish when the workday begins. Common approaches:

Workday Start	Typical Use Case
12:00 AM (midnight)	Default, administrative simplicity
Start of first shift	Manufacturing, consistent shift operations
6:00 AM or 7:00 AM	Day-shift focused operations
Time aligned with majority of workforce	Mixed operations

Considerations for Choosing a Workday Start

Operational alignment:

• When do most employees start work?
• Are there overnight operations?
• Do shifts cross the current workday boundary?

Compliance factors:

• How will the workday affect overtime calculations?
• Will it create unintended overtime for certain shifts?
• Does it align with meal period requirements?

Administrative simplicity:

• Midnight start aligns with calendar dates
• Shift-start alignment may be easier for scheduling
• Payroll systems may have default assumptions

How the Workday Affects Overtime

Standard Day Shift Example

Workday: Midnight to midnight

Time	Activity	Workday
8:00 AM	Clock in	Day 1
12:00 PM	Meal break	Day 1
5:00 PM	Clock out	Day 1

Result: 8.5 hours (with 30-min meal) = 30 minutes daily overtime

Overnight Shift Example

Workday: Midnight to midnight

Time	Activity	Workday
10:00 PM	Clock in	Day 1
12:00 AM	Midnight	Day 2 begins
3:00 AM	Meal break	Day 2
6:00 AM	Clock out	Day 2

With midnight workday:

• Day 1: 2 hours (10 PM - midnight)
• Day 2: 7.5 hours (midnight - 6 AM, minus 30-min meal)
• No daily overtime (neither day exceeds 8 hours)

With 10 PM workday start:

• Workday: 9.5 hours total (one workday)
• 1.5 hours daily overtime (hours 8.01-9.5 at 1.5x)

This is why workday definition matters significantly.

Swing Shift Example

Workday: Midnight to midnight

Time	Activity	Workday
3:00 PM	Clock in	Day 1
7:30 PM	Meal break	Day 1
12:30 AM	Clock out	Day 2

Result:

• Day 1: 9 hours (3 PM - midnight, minus 30-min meal)
• Day 2: 30 minutes (midnight - 12:30 AM)
• 1 hour daily overtime on Day 1

Changing the Workday

When Changes Are Permitted

Employers may change the workday start time, but:

• It must not be done to avoid overtime
• The change should be for legitimate business reasons
• It should be communicated to employees
• It should be applied consistently going forward

Prohibited Manipulation

Changing the workday to reduce overtime is illegal in California:

Example of prohibited change:

An employer notices that overnight shifts consistently generate overtime because 10 hours of work falls within one workday. The employer changes the workday start to split the shift across two workdays, each under 8 hours.

This is illegal because the purpose is to avoid paying earned overtime.

Legitimate Reasons to Change

Legitimate Reason	Example
Operational change	Company moves from day shift to 24-hour operations
New facility	Different facility has different shift patterns
Business restructuring	Merger brings different workforce
System implementation	New time clock system requires alignment

Workday and Meal Periods

California's meal period rules depend on the workday:

First Meal Period

Must be provided no later than the end of the 5th hour of work in the workday:

Work Started	Meal Must Begin By
6:00 AM	10:59 AM
8:00 AM	12:59 PM
10:00 PM	2:59 AM next calendar day

Second Meal Period

Required when working more than 10 hours in a workday:

Situation	Second Meal Requirement
9-hour workday	Not required
10-hour workday	Can be waived if first meal taken
10+ hour workday	Required (waiver permitted in some cases)

Meal Period Tracking

Timesheets and time clocks must track meal periods within each workday, recording:

• When the meal period begins
• When the meal period ends
• Total meal duration (must be at least 30 minutes)

Multiple Workday Definitions

Can Different Employees Have Different Workdays?

Yes, but it must be:

• Based on legitimate operational differences
• Applied consistently within similar roles
• Not designed to avoid overtime

Example of permitted variation:

Employee Group	Workday Start	Rationale
Day shift production	6:00 AM	Aligned with shift start
Night shift production	6:00 PM	Aligned with shift start
Administrative staff	Midnight	Standard calendar day

Different Locations

Different facilities may have different workday definitions based on their operations:

Location	Workday	Reason
Headquarters	Midnight	Office hours
Factory A	5:00 AM	First shift start
Factory B	6:00 PM	Overnight operations

Workday vs. Workweek

California has separate definitions for workday and workweek:

Concept	Definition	Overtime Threshold
Workday	24 consecutive hours	8 hours daily
Workweek	7 consecutive 24-hour periods	40 hours weekly

Independent Calculations

Both must be tracked independently:

Example:

Day	Hours Worked	Daily OT	Running Weekly Total
Mon	9	1 hour	9
Tue	9	1 hour	18
Wed	9	1 hour	27
Thu	9	1 hour	36
Fri	7	0	43

Result:

• 4 hours daily overtime (one hour each Mon-Thu)
• 3 hours weekly overtime (hours 41-43)
• These don't stack—the 4 daily OT hours count toward the 40 regular

Common Workday Scenarios

Scenario 1: Double Shift

Employee works two shifts in one workday.

Workday: Midnight to midnight

Shift	Times	Hours
Morning	6 AM - 2 PM	8 (with 30-min meal = 7.5)
Evening	4 PM - 10 PM	6 (with 30-min meal = 5.5)

Total workday hours: 13

Overtime calculation:

• Hours 1-8: Regular rate
• Hours 8.01-12: 1.5x rate
• Hours 12.01-13: 2x rate

Scenario 2: On-Call Callback

Employee works regular shift, then is called back.

Workday: 7 AM to 7 AM

Activity	Times	Hours
Regular shift	7 AM - 3 PM	8 (with meal = 7.5)
Callback	10 PM - 1 AM	3

If callback is within same workday (before 7 AM):

• Total: 10.5 hours
• 2.5 hours daily overtime

If callback starts new workday (after 7 AM):

• Day 1: 7.5 hours (no OT)
• Day 2: 3 hours (no OT)

Scenario 3: Shift Spanning Two Workdays

Employee works shift that crosses workday boundary.

Workday: Midnight to midnight

Time Period	Hours	Workday
8 PM - midnight	4	Day 1
Midnight - 4 AM	4	Day 2

Result: 8 hours total, but split across two workdays

• Day 1: 4 hours (no daily OT)
• Day 2: 4 hours (no daily OT)

If workday started at 8 PM:

• One workday: 8 hours (still no daily OT, but all hours in same period)

Technology and Workday Tracking

Time Clock Configuration

Modern time clock systems must be configured for workday definition:

Setting	Description
Workday start time	When the 24-hour period begins
Department variations	If different groups have different workdays
Overtime calculation	Based on workday hours
Meal tracking	Tied to workday timing

Payroll System Alignment

Ensure payroll systems match workday definition:

• Timesheet reports organized by workday
• Overtime calculated per workday
• Daily summaries reflect true workday, not calendar day
• Reports available for compliance auditing

Common Configuration Errors

Error	Impact	Prevention
Mismatched time clock and payroll	Incorrect OT calculation	System integration testing
Calendar day assumed	Overnight shifts miscalculated	Explicit workday configuration
Inconsistent application	Compliance risk	Audit and standardize

Documentation Requirements

What to Document

Document	Content
Written policy	Workday definition for each employee group
Time records	Hours worked per workday
Payroll records	Overtime calculated by workday
Policy history	Any changes to workday definition

Record Retention

California requires 3-year retention (4+ years recommended) for:

• Time records showing workday hours
• Payroll records with overtime calculations
• Policies establishing workday definitions

Best Practices

Establish Clear Policies

1. Document the workday in writing for all employee groups
2. Communicate clearly to employees and managers
3. Include in handbook and onboarding materials
4. Post at workplace where relevant

Configure Systems Correctly

1. Align time clock with workday definition
2. Verify payroll calculations match workday-based overtime
3. Test scenarios (overnight, callbacks, double shifts)
4. Audit regularly for accuracy

Avoid Manipulation

1. Never change workday to avoid overtime
2. Document business reasons for any changes
3. Apply consistently to similar employees
4. Seek legal counsel if considering changes

Train Managers

Supervisors should understand:

• How the workday affects overtime
• Meal period timing requirements
• Why consistent application matters
• How to handle unusual scheduling situations

The Bottom Line

The California workday is more than a technicality—it's the foundation for daily overtime calculations and meal period compliance. A 24-hour consecutive period starting at a consistent time each day, the workday determines whether an employee has worked overtime and when meal breaks must be provided.

Employers have flexibility in setting the workday start time, but must do so for legitimate business reasons and apply it consistently. The workday cannot be manipulated to avoid paying overtime, and any changes must be documented and communicated.

Understanding and properly implementing the workday definition is essential for California compliance. Configure your time clock systems correctly, train managers on the concept, and ensure all overtime calculations are based on actual workday hours—not just calendar day hours. Getting this right protects both your employees' wages and your company's compliance standing.