Vietnamese Lunar Calendar Widget: Âm Lịch and Can Chi Explained

The Vietnamese lunar calendar, or âm lịch, is a lunisolar calendar: its months follow the phases of the moon, while leap months keep it aligned with the solar year. Millions of Vietnamese households still rely on it every month to know when Tết, the full moon (Rằm) and family death anniversaries fall. A lunar calendar widget puts that information on your home screen, so you can see today's lunar date at a glance instead of opening an app or checking a paper calendar.

This guide explains how âm lịch works, what can chi means, why the Vietnamese calendar is calculated differently from the Chinese one, and what a useful lunar widget should show.

#What is âm lịch?

Despite the name, âm lịch is not purely lunar. It is lunisolar, which means it combines two cycles:

• Months follow the moon. Each month begins on the day of the new moon, so a lunar month has either 29 or 30 days. The first day is called mùng 1, and the 15th, around the full moon, is Rằm.
• Years follow the sun. Twelve lunar months are about eleven days shorter than a solar year. To stop the calendar drifting through the seasons, a leap month (tháng nhuận) is inserted roughly every two to three years, giving that year thirteen months.

The result is a calendar that tracks the moon closely while keeping Tết in late winter or early spring every year. That is why Tết moves around on the solar calendar: it fell on 17 February in 2026 and will fall on 6 February in 2027.

#Why Vietnamese families still use it

Most daily life in Vietnam runs on the solar (Gregorian) calendar, but âm lịch shapes many of the moments that matter most.

• Tết Nguyên Đán. The Lunar New Year is the biggest holiday of the year, and its date is set by the lunar calendar.
• Mùng 1 and Rằm. Many families make offerings, visit pagodas or eat vegetarian meals on the first and fifteenth of each lunar month.
• Giỗ (death anniversaries). Ancestors are remembered on the lunar date of their passing, so the solar date changes every year. Families often need to look it up well in advance to gather relatives.
• Traditional festivals. Occasions such as the Mid-Autumn Festival follow lunar dates.
• Choosing dates. Some people consult the lunar calendar and can chi when picking days for weddings, moving house, opening a business or starting a long journey.

For anyone who lives abroad, works on a solar schedule, or simply forgets to check, a widget is the easiest way to keep these dates visible.

#Can chi explained

Can chi is the traditional system for naming years, months, days and even hours. It pairs two cycles.

#The 10 heavenly stems (can)

Giáp, Ất, Bính, Đinh, Mậu, Kỷ, Canh, Tân, Nhâm, Quý.

#The 12 earthly branches (chi)

Tý, Sửu, Dần, Mão, Thìn, Tỵ, Ngọ, Mùi, Thân, Dậu, Tuất, Hợi.

Each branch is linked to an animal of the zodiac. Stems and branches advance together, one step at a time, so a stem is always paired with a branch of matching position (odd with odd, even with even). Because 10 and 12 share a factor of 2, the combinations repeat every 60 steps. That is the famous 60-year cycle: a year named Bính Ngọ comes around once every sixty years.

The current lunar year is Bính Ngọ, a Horse year. As an example of how dates read, Saturday 10 October 2026 corresponds to mùng 1 tháng 9, the first day of the ninth lunar month, in the year Bính Ngọ.

#How the Vietnamese zodiac differs

The Vietnamese zodiac shares most of its animals with the Chinese one, with two well-known differences:

So someone born in a Mão year in Vietnam is a Cat, not a Rabbit, and a Sửu year belongs to the water buffalo, an animal at the heart of Vietnamese farming life.

#Why Vietnam's calendar uses UTC+7

A lunar month begins on the day the new moon occurs. The new moon is a single astronomical instant, but which calendar day it falls on depends on your time zone.

Vietnam calculates its lunar calendar for Vietnam time, UTC+7, while the Chinese calendar is calculated for UTC+8. Most of the time this one-hour difference changes nothing. Occasionally, though, a new moon happens shortly before midnight in Vietnam, which is already after midnight in China. When that happens, the lunar month starts on different solar days in the two countries, and in rare cases the difference can even shift a leap month or the date of Tết.

This is why a calendar app built for the Chinese calendar is not always correct for Vietnamese users. A Vietnamese lunar widget should do its calculations for UTC+7. WidgyKit's lunar calendar is calculated for Vietnam time for exactly this reason.

#What a good lunar calendar widget shows

Not every lunar widget is equally helpful. Here is what to look for, by size.

#Small

• Today's solar date and lunar date side by side
• The lunar month, marked if it is a leap month
• A clear highlight on mùng 1 and Rằm

#Medium

• Everything in Small
• Can chi of the day, month and year
• The next traditional holiday with a countdown in days

#Large

• A full month grid with lunar dates printed under each solar date
• Holidays and important days highlighted
• Can chi details for today

A good widget also keeps working offline, because lunar dates can be calculated on the device rather than downloaded. That means it is accurate on a flight or when you have no signal.

#Setting it up in WidgyKit

1. Install WidgyKit on your iPhone or Android phone and open it once so it can prepare your widgets.
2. Browse the lunar calendar templates and pick the style you like.
3. Go to your home screen and add the WidgyKit widget in the size you want. If you need a refresher, follow our steps for iPhone or Android.
4. Pair it with a countdown widget for an upcoming giỗ or Tết, so the next important family date is always in view. Our countdown widget ideas have more inspiration.

Because every WidgyKit widget shares one visual style, your lunar calendar matches your clock, weather and habit widgets. The "Vietnamese lunar and family" setup in our aesthetic home screen ideas is a good starting point.

#FAQ

#Is the Vietnamese lunar calendar the same as the Chinese one?

They share the same structure and are usually identical, but Vietnam calculates for UTC+7 and China for UTC+8, so the start of a month can occasionally differ by a day. The Vietnamese zodiac also has the Cat and the Buffalo.

#Do I need an internet connection?

No. Lunar dates and can chi can be calculated on your device, so the widget works offline.

#Can I see both calendars at once?

Yes. Most lunar widgets, including WidgyKit's, show the solar date alongside the lunar date.

#Wrapping up

Âm lịch is centuries old, but it still decides when families gather, pray and celebrate. Putting it on your home screen is a small change that helps you remember the dates that matter. Explore WidgyKit's widgets, including the Vietnamese lunar calendar, or read the FAQ to learn more.