AZCalc.net

Everyday Domain Calculator • AZCalc.net

Date Calculator

Calculate days between two dates, add or subtract time, calculate US business days with federal holiday exclusion, and plan project deadlines.

Tool Overview & Core Functionality

Solves calendar date differences, adds or subtracts day/month/year increments, and calculates elapsed time intervals with weekend and holiday filtration.

              Gregorian Calendar Interval and Boundary Math:
            
              Calendar Date Differential & Modular Offset Arithmetic

This calculator executes instantaneous, zero-latency computations strictly client-side. No financial balance, health metric, or personal chronological details are transmitted to external servers.

Admin Practical Note: Weekend Rollover Holidays

Observed vs Actual Federal Holiday Rules

Holiday falling on a Saturday: Statutorily observed on preceding Friday under 5 U.S.C. § 6103(b)
Holiday falling on a Sunday: Statutorily observed on subsequent Monday

Admin Practical Takeaway: Business day interval calculations must account for the observed holiday calendar, not just the nominal date.

Authoritative Regulatory Benchmarks & Primary Citations

Verified against statutory definitions, federal standards, and published clinical methodologies (CDC, WHO, NIH, ACOG):

U.S. House of Representatives Office of the Law Revision Counsel: 5 U.S. Code § 6103: Statutory Public Holidays and Observance Rules
Federal statutory definitions for official US holidays including weekend rollover observation rules (Friday/Monday).
U.S. Naval Observatory (USNO): Astronomical Applications Department: Gregorian Calendar Algorithm & Julian Day Counts
Exact astronomical day-count algorithms, leap second protocols, and duration between calendar epochs.

Frequently Asked Questions (Everyday)

Can I add business days excluding weekends?: Yes, our business days mode filters out Saturdays and Sundays to calculate true working schedules.