Comprehensive Calendar & Time Guide (Hijri, Gregorian, and Countdowns)
Five different needs that look similar: your age, the gap between two dates, a countdown to an upcoming event, calendar conversion, and night timing. This guide clarifies exactly when you need each one, and brings together the time and date calculators in one place.
Guide steps
Start here if you only need to convert a single date between the Hijri and Gregorian systems — this is the same conversion logic the age and last-third-of-the-night calculators below rely on internally.
Once you understand the conversion logic, calculate your exact age in both calendars at once, without a separate manual conversion step.
If your goal is measuring the duration between two past dates — not a person's age, not a countdown to a future event — this is the direct tool.
For a day-by-day countdown to a specific upcoming event — a wedding, a trip, an exam — use this instead of calculating the gap manually.
To calculate the timing of the last third of the night and midnight for any date and location, based on that day's actual Maghrib and Fajr times.
Two calendars in daily life: when do you need each one?
In Saudi Arabia, religious and national occasions (Ramadan, Hajj, National Day) run on the Hijri calendar, while most contracts, salaries, and daily official deadlines run on the Gregorian one. This dual system means almost everyone needs to move between the two on a near-weekly basis — from a Gregorian employment contract date to a Hijri family occasion.
The gap between the two calendars isn't fixed: the Hijri year is about 11 days shorter than the Gregorian year, so Hijri occasions shift about 11 days earlier in the Gregorian calendar every year (this year's Ramadan isn't on the same Gregorian date as last year's). That cumulative drift is the single biggest source of error for anyone converting manually or relying on memory from a previous year.
Three needs that look alike but aren't: age, date difference, and a countdown
Age is a special case of measuring duration: a fixed starting point (your birth date) against today, usually shown in both calendars. Date difference is more general: the gap between any two points in the past (a contract's start and end, a hire date and a resignation date), with no connection to anyone's age. Days remaining looks forward, not back: a countdown from today to a single future date.
A common mix-up happens when someone tries to use the date-difference calculator to work out their own age manually (entering their birth date and today), instead of using the dedicated age calculator, and misses useful details like seeing the age in both calendars at once. Each calculator here is built for a specific question; using the right tool saves you extra manual steps.
The basis for calculating the last third of the night
The Islamic night is measured from the Maghrib call to prayer to the following Fajr call, and is divided into three equal thirds. The last third — the recommended time for night prayer (qiyam) and supplication — begins after the first two-thirds and runs until Fajr.
Since Maghrib and Fajr times change every day (and differ between cities), the timing of the last third isn't a fixed number that works for every day or every location — so don't rely on a previous day's or a different city's calculation.
Quick tips
- The Hijri calendar advances by about 11 days each Gregorian year, so a fixed Hijri occasion (like Ramadan or National Day) falls on a different Gregorian date every year.
- If your birth certificate or contract is dated in Hijri, convert it to Gregorian first before calculating any duration or age, to avoid common manual-conversion mistakes.
- The timing of the last third of the night changes daily along with Maghrib and Fajr times, so don't rely on a fixed number from a previous day or a different city.
- To know your exact age in both calendars, don't just subtract years by hand — the day-count gap between the two systems makes manual calculation prone to being off by a day or more.
Frequently asked questions
What's the difference between the date-difference calculator and the Hijri-Gregorian converter?
Date difference computes the duration (days/months/years) between two dates, while the converter translates a single date between the Hijri and Gregorian systems without calculating any elapsed time. If you need both (two dates in different systems), convert first, then calculate the difference.
What's the difference between the age calculator and the date-difference calculator?
The age calculator is a special case built specifically to measure the span from your birth date to today, showing the result in both the Hijri and Gregorian calendars. The date-difference calculator is more general: it measures the gap between any two dates you choose (like a contract's start and end), with no special handling for anyone's age.
Why does the date of Ramadan or National Day change every Gregorian year?
Because the Hijri year (lunar) is about 11 days shorter than the Gregorian year (solar). That gap compounds annually, so every fixed Hijri occasion shifts about 11 days earlier in the Gregorian calendar each year — which is exactly why you regularly need an accurate date converter instead of relying on last year's date.
How do I find the exact days remaining until an upcoming Hijri occasion?
If the occasion's date is Hijri, convert it to Gregorian first with the converter, then enter the result into the days-remaining calculator for a precise day-by-day countdown.
Is the timing of the last third of the night the same in every city?
No. The timing depends on the Maghrib and Fajr call-to-prayer times at your specific location, which differ between cities (and even within the same city by a few minutes depending on longitude) — so calculate it for your own location and day, not a different city or date.
Does the age calculator compute Hijri age or Gregorian age?
Both, in the same result — your age in years, months, and days according to the Gregorian calendar, and also according to the Hijri calendar, since many milestones (like Islamic legal adulthood or a specific age on an official document) may be measured in one system but not the other.