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Rolex Datejust 31 68278 (18k yellow gold, white Roman dial) vs Rolex Day-Date 18238 (18k yellow gold, blue diamond dial)
Two timepieces compared — $10,000–$25,000 vs $25,000+
Quick Verdict
The Rolex Datejust 31 68278 (18k yellow gold, white Roman dial) ($10,000–$25,000) offers Rolex 2135, in-house automatic, chronometer precision in the tier below the Rolex Day-Date 18238 (18k yellow gold, blue diamond dial) ($25,000+). The Datejust 31 68278 (18k yellow gold, white Roman dial) measures 31mm and is rated 100m (10 ATM). The Day-Date 18238 (18k yellow gold, blue diamond dial) counters with Swiss Made craftsmanship and 100m (10 ATM) water resistance. Both are exceptional timepieces for their respective tiers.
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Specifications Compared
| Feature | Rolex Datejust 31 68278 (18k yellow gold, white Roman dial) | Rolex Day-Date 18238 (18k yellow gold, blue diamond dial) |
|---|---|---|
| Price | $10,000–$25,000 | $25,000+ |
| Case Size | 31mm | 36mm |
| Movement | Automatic, Rolex Calibre 2135 | Automatic, Rolex Calibre 3155 |
| Caliber Type | Rolex 2135, in-house automatic, chronometer | Rolex 3155, in-house automatic, chronometer |
| Power Reserve | About 42 hours | About 48 hours |
| Water Resistance | 100m (10 ATM) | 100m (10 ATM) |
| Crystal | Sapphire Crystal, Cyclops | Sapphire Crystal, Cyclops |
| Case Material | 18k yellow gold, fluted bezel | 18k yellow gold |
| Origin | Swiss Made | Swiss Made |
Category-by-Category Analysis
Design & Aesthetics
Rolex's design language vs Rolex's approach
The Rolex Datejust 31 68278 (18k yellow gold, white Roman dial) features a 18k yellow gold, fluted bezel case at 31mm with Sapphire Crystal, Cyclops protection. The Rolex Day-Date 18238 (18k yellow gold, blue diamond dial) offers 18k yellow gold construction at 36mm with Sapphire Crystal, Cyclops. Both represent their brand's distinct design philosophy and heritage.
Movement & Performance
Automatic, Rolex Calibre 2135 vs Automatic, Rolex Calibre 3155
The Datejust 31 68278 (18k yellow gold, white Roman dial) runs the Automatic, Rolex Calibre 2135 (Rolex 2135, in-house automatic, chronometer, About 42 hours power reserve) at standard frequency. The Day-Date 18238 (18k yellow gold, blue diamond dial) uses the Automatic, Rolex Calibre 3155 (Rolex 3155, in-house automatic, chronometer, About 48 hours reserve) at standard. The Day-Date 18238 (18k yellow gold, blue diamond dial) offers a longer power reserve.
Wearability & Fit
31mm vs 36mm — different wrist presence
At 31mm, the Datejust 31 68278 (18k yellow gold, white Roman dial) wears more compactly on smaller wrists compared to the Day-Date 18238 (18k yellow gold, blue diamond dial) at 36mm. Water resistance differs: 100m (10 ATM) vs 100m (10 ATM).
Value & Cost of Ownership
Rolex sits in the lower tier
The Rolex Datejust 31 68278 (18k yellow gold, white Roman dial) sits at $10,000–$25,000 and the Rolex Day-Date 18238 (18k yellow gold, blue diamond dial) at $25,000+. On the specs that outlast any price: the Datejust 31 68278 (18k yellow gold, white Roman dial) uses Sapphire Crystal, Cyclops with About 42 hours, against Sapphire Crystal, Cyclops and About 48 hours on the Day-Date 18238 (18k yellow gold, blue diamond dial). Service intervals are typically 5-7 years for both.
Water Resistance
100m (10 ATM) vs 100m (10 ATM)
The Datejust 31 68278 (18k yellow gold, white Roman dial) is rated to 100m (10 ATM) while the Day-Date 18238 (18k yellow gold, blue diamond dial) handles 100m (10 ATM). Both offer identical water resistance ratings.
Our Verdict
Rolex
Datejust 31 68278 (18k yellow gold, white Roman dial)
Choose the Rolex Datejust 31 68278 (18k yellow gold, white Roman dial) if you prioritize Rolex 2135, in-house automatic, chronometer engineering, Swiss Made craftsmanship, and 100m (10 ATM) water resistance. At $10,000–$25,000, it delivers Automatic, Rolex Calibre 2135 with About 42 hours power reserve.
Check Price on AmazonRolex
Day-Date 18238 (18k yellow gold, blue diamond dial)
Choose the Rolex Day-Date 18238 (18k yellow gold, blue diamond dial) if you value Rolex 3155, in-house automatic, chronometer technology, Swiss Made heritage, and 36mm proportions. At $25,000+, the Automatic, Rolex Calibre 3155 with About 48 hours power reserve makes it a compelling choice.
Check Price on AmazonThe Bottom Line
The Rolex Datejust 31 68278 (18k yellow gold, white Roman dial) and Rolex Day-Date 18238 (18k yellow gold, blue diamond dial) represent two distinct approaches to the timepiece category — the Rolex bringing Swiss Made tradition while Rolex delivers Swiss Made engineering.
Frequently Asked Questions
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How This Page Was Made
Our comparisons are generated from a hand-maintained specification database and reviewed under our editorial standards. We use AI tools to assemble pages from that data. We don’t invent specs: every number traces back to the database, and when we correct an entry, the fix is applied site-wide. As an Amazon Associate, The Horologist earns from qualifying purchases.