Watch Almanac
Hamilton

Khaki Aviation Pilot Day Date Auto 42mm

Ref. H64635140

Case diameter
42 mm
Manufacturer spec
Lug-to-lug
51 mm
Measured in a published review
Thickness
12.1 mm
Manufacturer spec
Lug width
20 mm
Manufacturer spec

Retail price $1,125 (US, Oct 2026)

Ideal fit
Wrist flat: 55.1 mmLug-to-lug: 51 mm

How the Khaki Aviation Pilot Day Date Auto 42mm wears

Its lugs reach 9 mm past the 42 mm case, more than the 7.1 mm typical across the almanac, so it wears larger than its diameter suggests.

On our fit model it sits best on wrists from 7" to 8.5" (17.8–21.6 cm); below 7" the lugs start to reach the edge of the wrist.

At 12.1 mm thick it is slimmer than 57% of the 14 other pilot watches we've measured, so it slides under a cuff more easily than most.

Its 20 mm lug width is one of the most common strap sizes; 104 other watches here share it, so aftermarket straps are easy to find.

Will the Khaki Aviation Pilot Day Date Auto 42mm fit your wrist?

With a 51 mm lug-to-lug, here is how it wears across common wrist sizes. We estimate the flat top of each wrist from its circumference; measure yours for a closer answer in the fit finder.

WristFlat width (est.)Fit
6"47.2 mmLugs overhang
6.5"51.2 mmLugs overhang
7"55.1 mmIdeal fit
7.5"59.1 mmIdeal fit
8"63 mmIdeal fit

Specifications

Reference
H64635140
Collection
Khaki Aviation
Status
In production
Introduced
2024
Case material
stainless steel
Crystal
sapphire
Water resistance
100 m
Bezel
fixed
Dial
blue
Strap / bracelet
stainless steel bracelet, folding clasp
Style
Pilot, Everyday

Movement

Caliber
ETA (Hamilton) H-30
Type
automatic
Power reserve
80 hours
Jewels
25

Takes 20 mm straps. See other 20 mm watches and straps.

More Khaki Aviation references

Watches that wear the same size

Other watches within 1.5 mm of its lug-to-lug.

Same 20 mm lug width

All 20 mm watches

These take the same straps as the Khaki Aviation Pilot Day Date Auto 42mm.

Sources