About Ngay Viet

Ngay Viet is a lunar and Gregorian calendar for Vietnamese users: lunar dates, holidays, traditional events and sale campaigns in one place, usable offline.

What the free version includes

• A month calendar showing Gregorian and Vietnamese lunar dates side by side.
• Vietnamese holidays, clearly separating commemorations from statutory days off.
• Lunar events: new moon days, full moon days, Tet and traditional festivals.
• Sale calendar for major e-commerce platforms.
• Installable as an app, with previously loaded data available offline.

How the lunar calendar is computed

Lunar dates are computed with the astronomical algorithm standardised by Ho Ngoc Duc, based on Jean Meeus's Astronomical Algorithms. The first day of a lunar month is the day containing the new moon, the eleventh lunar month is the one containing the winter solstice, and every computation is pinned to UTC+7 so results do not change with your location.

Data sources

Holidays and statutory days off follow Article 112 of the 2019 Labour Code. Compensatory days off and the exact Tet break are announced by the Government each year, so they are only added once an official document exists — Ngay Viet does not guess them.

Dataset last updated: 2026-07-28

About the sale calendar

Double-day sales are marked as expected based on the yearly cycle, not as official announcements from the platforms for a given year. Ngay Viet is not an official partner of Shopee, Lazada or TikTok Shop, and makes no claims about discount levels. Some shopping links are affiliate links provided by Rewaffi; this is always disclosed next to the button.

What's next

We plan to add more event topics, reminders and a mobile app. The current free version has no accounts, collects no personal data and shows no ads.

Contact

For feedback or data corrections, please visit https://ngayviet.app