December closes the year with the highest sales volume and the shortest attention span of any month.
Christmas falls on Saturday 25 December 2027 and New Year's Eve on Friday the 31st both landing at the end of the week, which stretches the season into two long weekends. Before that come World AIDS Day on the 1st, Human Rights Day on the 10th, and the solstice on the 21st.
To help you plan your brand's campaigns, Instagram giveaways and social media content, we've put together the complete calendar of special days in December 2027.
Special days in December 2027
1 December (Wednesday)
WORLD AIDS DAY 🎗️ (WHO)
Eat a Red Apple Day 🍎
2 December (Thursday)
International Day for the Abolition of Slavery ✊🏾 (UN)
Fritters Day 🍩
3 December (Friday)
INTERNATIONAL DAY OF PERSONS WITH DISABILITIES ♿ (UN)
Make a Gift Day 🎁
4 December (Saturday)
International Day of Banks 🏦 (UN)
World Wildlife Conservation Day 🐘
5 December (Sunday)
INTERNATIONAL VOLUNTEER DAY 🤲 (UN)
World Soil Day 🌱 (UN)
6 December (Monday)
St Nicholas Day 🎅
Miners' Day ⛏️
7 December (Tuesday)
International Civil Aviation Day ✈️ (UN)
Letter Writing Day ✉️
8 December (Wednesday)
Immaculate Conception ⛪
Pretend to Be a Time Traveler Day 🕰️
9 December (Thursday)
International Anti-Corruption Day 🚫 (UN)
International Day of Commemoration of the Victims of Genocide 🕯️ (UN)
10 December (Friday)
HUMAN RIGHTS DAY ✊ (UN)
Nobel Prize Day 🏅
11 December (Saturday)
International Mountain Day ⛰️ (UN)
UNICEF Day 🧒
12 December (Sunday)
International Universal Health Coverage Day 🏥 (UN)
International Day of Neutrality 🕊️
13 December (Monday)
St Lucia's Day 🕯️
Violin Day 🎻
14 December (Tuesday)
Monkey Day 🐒
International Shareware Day 💾
15 December (Wednesday)
International Day of the Ninja 🥷
Cat Herders Day 🐈
16 December (Thursday)
Chocolate Covered Anything Day 🍫
17 December (Friday)
Wright Brothers Day ✈️
Maple Syrup Day 🥞
18 December (Saturday)
INTERNATIONAL MIGRANTS DAY 🌍 (UN)
Arabic Language Day 🗣️ (UN)
19 December (Sunday)
Fourth Sunday of Advent ⛪
Look for an Evergreen Day 🌲
20 December (Monday)
International Human Solidarity Day 🤝 (UN)
Go Caroling Day 🎶
21 December (Tuesday)
SOLSTICE — winter in the north, summer in the south ❄️☀️
International Day of Meditation 🧘 (UN)
World Basketball Day 🏀 (UN)
23 December (Thursday)
Festivus 🎄
Roots Day 🌳
24 December (Friday)
CHRISTMAS EVE 🎄
25 December (Saturday)
CHRISTMAS DAY 🎁 (a public holiday in most of the world)
26 December (Sunday)
Boxing Day 🎁
St Stephen's Day ⛪
27 December (Monday)
International Day of Epidemic Preparedness 🦠 (UN)
Visit the Zoo Day 🦁
31 December (Friday)
NEW YEAR'S EVE 🎆
World Peace Meditation Day 🕊️
Social media post ideas for December 2027
December has the highest purchase intent of the year and the least available attention, which is a difficult combination. The brands that do well arrive early campaigns built in November and live by the first week and then change register halfway through the month. The first half is commercial; the second half, from roughly the 20th, belongs to gratitude, community and year-in-review content, which consistently outperforms offers once the buying is done.
Christmas falls on a Saturday and New Year's Eve on a Friday, which is unusually favourable: both create natural long weekends, and the shipping cut-off in most markets lands around 22 December, so the conversion window closes earlier than the calendar suggests. Plan the last delivery-guaranteed offer for the 20th rather than the 23rd.
International Day of Persons with Disabilities on 3 December deserves more attention than it usually gets from brands. Like Global Accessibility Awareness Day in May, it's a natural moment to audit your own site, app, packaging and content and posting about it without having done so is very visible.
The solstice on 21 December is the year's last good dual-hemisphere date: deep winter for half your audience, high summer for the other. It coincides with the International Day of Meditation and World Basketball Day, giving you three quite different angles on the same date.
Giveaway dates and campaign ideas for December
December rewards mechanics that bring people back rather than one big moment. An advent-calendar giveaway running from 1 to 24 December, with a small prize each day, produces the highest retention of any format on the calendar, because it gives people a reason to return daily for over three weeks.
A gift-guide giveaway in the first two weeks catches the audience while there's still time to ship. A charitable giveaway around International Volunteer Day on 5 December or Human Rights Day on the 10th fits the season's mood without competing on discount.
And a thank-you giveaway from 29 to 31 December, aimed at the people who engaged with you all year, is the most natural way to close the season and open January with an active community.
With Simpliers you can run Instagram giveaways in seconds, transparently and verifiably.
