May is the biggest commercial month of the first half of the year, and the one where global campaigns most often go wrong because Mother's Day is not on the same date everywhere.
In 2027 the largest cluster falls on Sunday 9 May, but a dozen major markets are on different days entirely. The month also holds Orthodox Easter on 2 May, Eid al-Adha on around 16 May, Star Wars Day on the 4th and World No Tobacco Day to close.
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 May 2027.
Special days in May 2027
1 May (Saturday)
INTERNATIONAL WORKERS' DAY ✊ (a public holiday across most of the world)
Free Comic Book Day 💥 (first Saturday)
Global Love Day 💗
2 May (Sunday)
ORTHODOX EASTER 🐣
World Laughter Day 😂 (first Sunday)
3 May (Monday)
WORLD PRESS FREEDOM DAY 📰 (UN)
World Sun Day ☀️
International Wild Koala Day 🐨
4 May (Tuesday)
STAR WARS DAY 🌌 ("May the Fourth be with you")
World Asthma Day 🫁 (first Tuesday)
International Firefighters' Day 🚒
5 May (Wednesday)
International Day of the Midwife 👶
World Portuguese Language Day 🗣️ (UNESCO)
Cinco de Mayo 🌮
Revenge of the Fifth ⚔️
6 May (Thursday)
Ascension Day ✝️ (a public holiday in much of Europe)
World Password Day 🔐 (first Thursday)
International No Diet Day 💚
7 May (Friday)
World Athletics Day 🏃
8 May (Saturday)
World Red Cross and Red Crescent Day ✚
World Migratory Bird Day 🐦 (second Saturday)
World Fair Trade Day 🤝 (second Saturday)
World Ovarian Cancer Day 💜
9 May (Sunday)
MOTHER'S DAY 💐 (second Sunday — in the US, most of Latin America, Canada, Australia, Japan, India, Türkiye, Germany, Italy and many more)
Europe Day 🇪🇺
10 May (Monday)
Mother's Day in Mexico, Guatemala and El Salvador 💐
World Lupus Day 💜
11 May (Tuesday)
Twilight Zone Day 📺
Eat What You Want Day 🍔
12 May (Wednesday)
INTERNATIONAL NURSES DAY 👩⚕️
International ME/CFS Awareness Day 💙
Limerick Day 📝
13 May (Thursday)
World Cocktail Day 🍸
International Hummus Day 🧆
14 May (Friday)
Chicken Dance Day 🐔
World Topiary Day 🌳
15 May (Saturday)
INTERNATIONAL DAY OF FAMILIES 👨👩👧 (UN)
International Conscientious Objectors Day 🕊️
16 May (Sunday)
EID AL-ADHA 🐑 (subject to the sighting of the moon)
Pentecost — Whitsunday ✝️
International Day of Light 💡 (UNESCO)
International Day of Living Together in Peace 🕊️ (UN)
17 May (Monday)
World Telecommunication and Information Society Day 📡 (UN)
World Hypertension Day 🩺
Whit Monday ✝️ (a public holiday in much of Europe)
18 May (Tuesday)
INTERNATIONAL MUSEUM DAY 🏛️
World AIDS Vaccine Day 🎗️
19 May (Wednesday)
World Family Doctor Day 🩺
World IBD Day 💜
20 May (Thursday)
WORLD BEE DAY 🐝 (UN)
Global Accessibility Awareness Day ♿ (third Thursday)
World Metrology Day 📏
21 May (Friday)
World Day for Cultural Diversity for Dialogue and Development 🌍 (UN)
INTERNATIONAL TEA DAY 🍵 (UN)
Endangered Species Day 🦏 (third Friday)
World Meditation Day 🧘
22 May (Saturday)
INTERNATIONAL DAY FOR BIOLOGICAL DIVERSITY 🌱 (UN)
World Goth Day 🖤
23 May (Sunday)
World Turtle Day 🐢
International Day to End Obstetric Fistula 🎗️ (UN)
24 May (Monday)
World Schizophrenia Day 💚
Brother's Day 👬
25 May (Tuesday)
Africa Day 🌍
Geek Pride Day 🤓
Towel Day 🧻 (for Douglas Adams)
International Missing Children's Day 💚
World Thyroid Day 🦋
26 May (Wednesday)
World Otter Day 🦦 (last Wednesday)
World Lindy Hop Day 💃
27 May (Thursday)
Sunscreen Day 🧴
28 May (Friday)
International Day of Action for Women's Health ♀️
World Hunger Day 🍚
29 May (Saturday)
International Day of United Nations Peacekeepers 🕊️ (UN)
World Digestive Health Day 🩺
Mount Everest Day 🏔️
30 May (Sunday)
World MS Day 🧡
31 May (Monday)
WORLD NO TOBACCO DAY 🚭 (WHO)
World Parrot Day 🦜
Smile Day 😊
Social media post ideas for May 2027
Mother's Day is the commercial centre of the month and the easiest thing in the calendar to get wrong at scale. A single global send on 9 May reaches Spain and Portugal a week late, Mexico a day early, France three weeks early and the UK three months late.
Segment by market or don't send at all. Two other things are worth planning for: the buying window closes on the Friday before, not the weekend itself; and an opt-out option letting people quietly mute Mother's Day emails has become standard practice for good reason, since the date is painful for a significant part of any audience.
Eid al-Adha falls on around 16 May, the second and larger of the two Eids, centred on sacrifice, sharing and family gatherings. As with Ramadan, the exact date depends on the sighting of the moon.
Orthodox Easter on 2 May opens the month for Greece, Eastern Europe and the Orthodox diaspora, and Vesak on 26 May is the most sacred day of the Buddhist calendar, though the observed date varies between countries.
Star Wars Day on 4 May is the single best performing pop culture date of the year for brands whose tone can carry it the pun does most of the work, and audiences expect it rather than resent it. It's followed by Revenge of the Fifth on the 5th for anyone who wants a second beat.
May is the strongest month of the year for health and wellbeing content, and the dates are unusually credible: International Nurses Day on the 12th, World Bee Day on the 20th, Mental Health Awareness Month across the whole month, and World No Tobacco Day on the 31st.
Global Accessibility Awareness Day on 20 May deserves particular attention it's the one day of the year when auditing your own site, app and social content for accessibility is both on-topic and genuinely useful, and posting about it without having done that audit is very visible.
Giveaway dates and campaign ideas for May
May is the month to run several small, well-targeted giveaways rather than one big one.
Build a Mother's Day giveaway per market rather than per region 9 May for the largest cluster, 10 May for Mexico and Central America, 2 May for Spain and Portugal, 30 May for France because a mistimed Mother's Day campaign reads as carelessness.
Run a Star Wars Day giveaway on 4 May, which needs almost no build-up to perform. Time a wellbeing or self care giveaway to Mental Health Awareness Week in mid-May. And close with a light, fast giveaway on International Tea Day, 21 May, or World Turtle Day, 23 May.
With Simpliers you can run Instagram giveaways in seconds, transparently and verifiably.
