Which tool to use
The time card calculator takes a start time, end time and unpaid break for each day, including overnight shifts, and totals the week in hours and minutes and in decimal hours. It then splits the hours into regular time, overtime at 1.5x and double time at 2x, using either the federal rule (over 40 hours a week) or California rules (daily overtime over 8 and 12 hours and the seventh-day rule), and shows the gross pay. You can print the sheet or copy it as CSV.
The UK holiday entitlement calculator works out statutory paid holiday of 5.6 weeks a year, capped at 28 days, for fixed days, fixed or compressed hours and shift patterns, for a full year or for starting or leaving part way through. Irregular-hours and part-year workers can add up the 12.07% of hours accrued in each pay period.
About these tools
Both tools run in your browser and cite the official rules they use: the U.S. Department of Labor and California Department of Industrial Relations for overtime, and GOV.UK for holiday entitlement, each with a last-checked date. Results are estimates for general information, not legal advice; contracts and other states or countries can give different rights.