Apostrophe in dates

Short answer

Do not use an apostrophe to pluralize years or decades. Use an apostrophe only when digits are omitted ('90s) or to show true possession (2021's). When possession sounds awkward, rewrite to of + year or place the year before the noun.

Plural decade: 1990s (not 1990's).
Abbreviated decade: '90s (apostrophe replaces the 19).
Possessive year: 2021's results = acceptable; The results from 2021 = often clearer.

Core explanation: plural decades, omitted digits, and possession

Plural decades and full-year plurals never take an apostrophe. Apostrophes mark either omission (shortened years) or possession-not plurality.

Use an apostrophe at the start of an abbreviated year ('80s = 1980s). Use an apostrophe for possession (2021's challenges), but prefer rephrasing if it improves clarity.

Plural decade: 1990s → no apostrophe.
Shortened decade: '90s → apostrophe replaces the leading digits.
Possessive: 2021's → the year possesses something; rewrite as the events of 2021 when helpful.

Wrong: The 1990's launched several tech trends.
Right: The 1990s launched several tech trends.
Wrong: 90's fashion came back this season.
Right: '90s fashion came back this season.

Formatting: hyphenation, spacing, and apostrophe glyphs

Never put spaces around an apostrophe in dates. Place the apostrophe directly before the shortened digits: '80s. For possessive plurals, place the apostrophe after the final s: the 1990s' influence.

Typographic (curly) apostrophes are preferred in print; straight apostrophes are common online. The exact glyph matters less than correct placement and spacing.

Wrong: 1990 's or 1990 s.
Correct: 1990s or 1990s'.
If you abbreviate a year in formal writing, prefer the full year (2007) over '07.
Possessive decades: the 1980s' style (apostrophe after the s).

Examples: common wrong → right pairs (copyable)

Short pairs you can paste directly to fix a sentence.

Wrong: The 1970's music scene was wild.
Right: The 1970s music scene was wild.
Wrong: Our '00's strategy failed.
Right: Our 2000s strategy failed.
Wrong: 2019's survey showed a rise in remote work.
Right: The 2019 survey showed a rise in remote work.
Wrong: Class of 2005's alumni met last week.
Right: The alumni of the Class of 2005 met last week.
Wrong: Get the 90's hits playlist ready.
Right: Get the '90s hits playlist ready.
Wrong: 2022's KPI shows growth.
Right: The 2022 KPIs show growth.

Real usage and style guides (news, academic, and corporate)

Style choices vary by context. Pick a convention and apply it consistently across a document or team.

News (AP): use '60s for abbreviated decades; never 1960's for a plural.
Chicago: prefers full decades (1960s) in formal prose; use apostrophes only for omission or possession.
Corporate: favor full years or rephrases (the 2021 budget) to reduce ambiguity.

Usage: AP headline: Artists from the '60s return. Academic title: 1960s Popular Music Revisited.
Usage: Corporate doc: The 2010s experienced a shift → better than The 2010's experienced a shift.

Workplace examples (wrong → right)

Business writing benefits from clarity. When a year acts like an adjective, drop the apostrophe for plurals and rephrase possessives.

Financials: use Q4 2020 results or 2020 Q4 results - avoid 2020's Q4 numbers.
Reports: use 1990s or '90s consistently across slides.
Legal/compliance: write the regulations from 2018 instead of 2018's regulations when possible.

Work - Wrong: 2020's Q4 numbers surprised analysts. Work -
Right: Q4 2020 numbers surprised analysts.
Work - Wrong: Please review the 2019's compliance checklist. Work -
Right: Please review the 2019 compliance checklist.
Work - Wrong: The 1990's influence is noted in the market study. Work -
Right: The 1990s' influence is noted in the market study.

Try your own sentence

Read the whole sentence aloud. Context usually reveals whether you mean plural, abbreviated, or possessive.

School and academic examples (wrong → right)

Use full years in formal writing and apostrophes only for clear abbreviations or possession handled carefully.

Class years: Class of '99 is fine; Class of 99's sounds awkward-prefer the reunion of the Class of 1999.
Essays: write 1990s or the 1990s; avoid informal '90s unless the tone allows it.
Citations and bibliographies: use full years (2007), not '07.

School - Wrong: The class of 99's president spoke at graduation. School -
Right: The Class of '99 president spoke at graduation.
School - Wrong: Students of the 90's examined cultural change. School -
Right: Students of the '90s examined cultural change.
School - Wrong: Research in the 2000's focused on early web tech. School -
Right: Research in the 2000s focused on early web tech.

Casual writing and social media examples (wrong → right)

Social posts can be informal, but common punctuation mistakes still distract. Use '90s or 1990s appropriately; avoid 1990's as a plural.

Hashtags often drop punctuation (#90sHits). That's fine-keep captions consistent.
In captions, '60s reads cleaner than 60's or 60s if you want to be correct.
Born-in bios: Born in the '80s rather than Born in the 80s'.

Casual - Wrong: I miss the 90's vibe. Casual -
Right: I miss the '90s vibe.
Casual - Wrong: My mom's 1980's photos are the best. Casual -
Right: My mom's 1980s photos are the best.
Casual - Wrong: Born in the 80s'. Casual -
Right: Born in the '80s.

Rewrite Help: a 3-step checklist plus copyable rewrites

Quick checklist to fix most errors: identify intent, apply the correct form, and rewrite if it sounds awkward.

Step 1 - Identify intent: plural decade, omitted digits, or possession?
Step 2 - Apply the form: 1990s (plural) / '90s (abbreviation) / 1990's or the events of 1990 (possession/rewrite).
Step 3 - If it reads oddly, rewrite to of + year or move the year before the noun.

Rewrite:
Original: The 1990's fashion was bold. → 1990s fashion was bold. OR Fashion in the 1990s was bold.
Rewrite:
Original: 2020's results show a drop. → The results from 2020 show a drop. OR 2020 results show a drop.
Rewrite:
Original: Class of 99's reunion is next month. → The Class of '99 reunion is next month. OR The reunion for the Class of 1999 is next month.

Memory trick and quick decision guide

Ask yourself: Am I pluralizing, shortening, or showing possession? Follow this simple rule: plural = no apostrophe; shortened = apostrophe at the start; possessive = apostrophe or rewrite.

Plural? NO apostrophe (1990s).
Shortened? APOSTROPHE at the start ('90s).
Possessive? APOSTROPHE to show ownership (2022's), but prefer of + year for clarity.

Tip: Think "P-S-O": Plural = Skip apostrophe; Shorten = Start with apostrophe; Ownership = Show apostrophe or rewrite.

Similar mistakes and quick grammar notes

Writers also misapply apostrophes to plural abbreviations, confuse ordinals with possession, or misplace possessive punctuation with decades.

Plural abbreviations: PhDs (not PhD's) unless showing possession.
Ordinals: 4th, 21st - ordinals do not use apostrophes.
Possessive decade: the 1980s' style (apostrophe after the s) when the decade as a whole owns something.
Prefer full forms in formal writing (2007 instead of '07).

Wrong: We invited PhD's to the seminar.
Right: We invited PhDs to the seminar.
Wrong: Write the 1990's influence was strong.
Right: Write the 1990s' influence was strong.

FAQ

Do I put an apostrophe in 2000s?

No. For the full decade, write the 2000s without an apostrophe. Use an apostrophe only if you abbreviate the decade ('00s), though many writers avoid that shortened form for clarity.

Is it '90s or 90s - do I need an apostrophe?

Use '90s to indicate omitted digits. Writing 90s without an apostrophe is common online; avoid 90's for a plural because that is incorrect in formal writing.

Can I write 2021's results?

Yes; 2021's results is a valid possessive. In formal or technical writing, the results from 2021 or the 2021 results often reads more clearly.

How should I write the reunion for a class year?

Class of '99 is fine for an abbreviated year. For possession, prefer the reunion of the Class of 1999 or the Class of '99 reunion depending on tone and formality.

Where should I look for official guidance?

Follow your organization's style: AP for journalism, Chicago for publishing. When unsure, favor clarity-use the full year or an of + year rewrite.

Still unsure about a sentence?

Paste one sentence into a grammar checker or use the Rewrite Help checklist: identify intent (plural/shortened/possessive), apply the correct form, and read it aloud. Copy one of the rewrites above and adapt it-this fixes most apostrophe-in-dates errors instantly.