Convert dates between 13 calendars and get Islamic, Jewish, Chinese and Persian holiday dates (Ramadan, Eid, Passover, Chinese New Year, Nowruz) for 1900-2100.

Count working days between two dates or add business days to a date, skipping weekends and public holidays of 100+ countries and regions.

One API to look up U.S. federal GSA per-diem (travel lodging + M&IE) and HUD Fair Market Rent / Small Area FMR (rent by bedroom, with voucher payment-standard bands) for any ZIP code — joined in a single call. FY2026, public-domain data, clean JSON. Built for travel-nurse stipend, relocation/HR, and real-estate/Section-8 tools. Unofficial; not affiliated with GSA or HUD.

Search live Poshmark fashion resale listings by keyword. Filter by brand, category, and price range. Returns item title, brand, size, price, original price, condition, seller, like and comment.

EPC label, EPBD MEPS compliance, and stranding-risk screening across 8 EU markets — primary energy, solar obligation, renovation cost, and cap-rate discount modelling for lenders and asset managers.

Search and browse U.S. government surplus auctions from GSA.gov. Find vehicles, electronics, equipment, and more at below-market prices.

Look up public holidays for 55 countries, calculate business day deadlines, find the next business day, export holidays to iCal, and more — all backed by versioned JSON data with no external dependencies at runtime. Covers 55 countries across Africa, Americas, Asia, Europe and Oceania for years 2024 to 2027.

Search for estate sales across the US. Find upcoming sales by city, state, or ZIP code. Get sale details including dates, addresses, photos, and descriptions from EstateSales.net.

Pregnancy due date and gestational age API. EDD from LMP, conception, IVF transfer day, or ultrasound CRL. ACOG redating rules, trimester, and term milestones. Deterministic ISO 8601 dates.

Optimize your acquisition strategies with our Acquisitions Focused Acquisitions Focused EU Building Energy Compliance API, ensuring energy-efficient properties.

Facilitate seamless compliance checks with our EU Building Energy Compliance API for Fund Compliance Teams designed specifically for Fund Compliance Teams.

Streamline your lending processes with our Lender Focused Lender Focused EU Building Energy Compliance API tailored for energy efficiency standards.

Gain valuable insights into building energy compliance with our Developer Insight Developer Insight EU Building Energy Compliance API for informed decisions.

Assess risk effectively using our EU Building Energy Compliance Risk Assessment API, safeguarding your investments against non-compliance.

Antenatal visit dates from the WHO 2016, NICE or ACOG published schedules, as calendar dates.

Applies ACOG Committee Opinion 700 Table 1 to decide whether an ultrasound overrides LMP dating.

Gestational age at any given date, returned as a 29w2d label and as total days.

Due date from embryo transfer date. Day-3, day-5, day-6 and egg retrieval calculated separately.

Ovulation estimate and 6-day fertile window from cycle length. Not contraceptive guidance.

Due date from last menstrual period using Naegele's rule, with 21-45 day cycle length correction.

Trimester boundaries, 24w0d viability, and four preterm and four term classes with their dates.

Dating from BPD, HC, AC and FL measurements in millimetres, using Hadlock 1984 equations.

Conception date from a last menstrual period or from a known due date, as ISO 8601 dates

Ensure timely project deliveries with the SLA Deadline Calculator, using global holidays for precise deadline calculations.

Calculate business days accurately while accessing global holiday data to optimize your workflows.