Navjeet Kamboj
Navjeet Kamboj is the author and editor of Age Calculator Lab. He focuses on making age, date, milestone and planning calculations easier to understand through clearly explained methods, practical examples and responsible limitations.
How these guides are presented
Complete inputs
Each explanation identifies the reference date, units and conventions needed to reproduce a result.
Practical examples
Worked examples show endpoint counting, month-end handling and time-zone boundaries.
Clear limits
Holiday coverage and organizational rules stay visible alongside general calendar arithmetic.
Practical date and time guides
All guidesDate Ranges: Overlap, Shared Endpoints and Midpoints
Compare two date ranges, choose an endpoint convention and calculate a halfway point. Worked examples explain touching ranges, contained ranges and odd-length intervals.
Quarters and Year Progress: Calendar Dates, Fiscal Starts and Percentages
Find quarter boundaries and measure calendar-period progress without fixed 90-day or 365-day shortcuts. Includes fiscal-start examples and leap-year comparisons.
Unix Timestamps vs Calendar Dates: Units, UTC and Conversion
Convert seconds and milliseconds without mixing up their units. Understand the Unix epoch, negative timestamps, UTC instants and date-only inputs.
Convert ISO Week Dates and Ordinal Days to Calendar Dates
Convert week-year/week/weekday values and year/day-number values correctly. Examples cover week 53, New Year boundaries, leap days and invalid inputs.
Work Hours, Breaks and Overnight Shifts: Calculate Elapsed Time
Calculate a dated shift, deduct the break you enter and interpret decimal hours. Includes overnight examples, input validation and daylight-saving limitations.
Add and Subtract Durations: Hours, Minutes, Seconds and Decimal Totals
Add or subtract elapsed amounts without treating minutes as decimals or wrapping at midnight. Includes carries, borrowing, negative totals and conversion checks.
Weekend Patterns and Working Calendars: Count the Right Dates
Separate weekday labels from working-day eligibility. Compare weekend patterns, holiday scope, custom closures and inclusive endpoints with a reproducible example.
PST to EST: Dates, Daylight Saving and Meeting Times
Convert Pacific and Eastern times with the right source date, distinguish fixed offsets from local zones, and resolve skipped or repeated hours before sharing a meeting.
Keep exploring
View the tool libraryDays Between Dates
Compare two dates with calendar days, complete weeks and weekday counts. Choose whether to include the end date.
Business Days Calculator
Count working days using your weekend pattern and optional excluded dates. Public holidays are excluded only when entered.
Day of the Week
Inspect a Gregorian date, leap-year rules, ISO week numbers and a printable month calendar.
Time Zone Converter
Convert an exact UTC instant to another IANA time zone.