ENJuly 21, 2026Mikail Aslan

NH36 Movement Explained: Day-Date, Specs & Mod Compatibility

NH36 day-date movement: published TMI specifications, accuracy limits, dial compatibility, donor-watch checks and how to compare the actual model.

Updated: October 17, 2026

Last fact-checked: October 9, 2026

The NH36 movement provides day and date in a mechanical automatic build. The calendar is the main reason to choose it over the date-only NH35. Choose by the functions and compatible components required for the actual watch, rather than by a claim that one calibre is universally better.

NH36 specifications

The TMI NH36 specification sheet and NH3 technical guide, retrieved on 9 October 2026, are the sources for these figures.

Specification	Published NH36A value
Display	Three hands, day and date
Winding	Automatic and manual
Stop seconds	Yes
Frequency	21,600 vibrations per hour
Jewels	24
Running time	More than 41 hours when fully wound
Outside diameter	27.40 mm
Casing diameter with dial holding spacer	29.36 mm
Height	5.32 mm
Stated static accuracy	−20 to +40 seconds per day under TMI's measurement conditions

The 2022 NH36A specification sheet states 23 ± 2 °C and a 20-second measurement for static accuracy. Separately, the 2025 NH3 guide describes testing 10–60 minutes after full winding in the dial-up, 9-up and 6-up positions, without an active calendar function; it gives no temperature condition. Regulation may change measured performance. Ask for the actual watch's measurement conditions and result if accuracy is a deciding factor; bench results and performance on the wrist need not be identical.

Day wheel and dial compatibility

To display both calendar functions, the dial opening must match the day/date layout. Wheel language, printing and orientation depend on the version fitted; verify the actual option instead of assuming a particular language combination.

A date-only dial does not automatically become mechanically unusable simply because the movement has a day wheel. It may hide the day display. Fit still depends on the dial feet, clearance, calendar opening and complete assembly. Conversely, an NH35 cannot provide a functioning day display merely because a dial has an extra opening.

Check dial, movement, hands, holder, case, stem and crown position as a system. Similar movement dimensions do not prove that a specific set of hands has the right length or clearance for a particular dial and crystal. Our NH35 vs NH36 comparison provides the manufacturer-based comparison.

Setting the calendar

At the first crown click, TMI shows date correction by turning left and day correction by turning right; the second click sets the hands. Do not quick-set the date between 21:00 and 04:00, as specified in the NH3 guide. That warning concerns date correction. Follow the instructions for the actual watch as well: a screw-down crown, if fitted, belongs to the case/crown assembly.

Buying a movement or using a donor watch

Compare current supplier offers for the exact movement version, included spacer, stem, wheel language and support.

Do not equate an original Seiko model's movement reference with the NH36 automatically. Seiko's SRPD55 specification names 4R36. If a donor watch has been modified, verify what is actually installed before buying parts.

Choosing a MedoMods model

Choose NH36 when you need a working weekday display as well as the date. If the date alone is enough, the MARINER MOD – BLACK uses NH35 and provides that function. The DAY MOD collection helps compare styling; confirm the calibre and working calendar on the individual product.

For other functions, compare the NH35 overview, GMT models and VK63 chronographs. Crystal, case, band and available options are model-dependent. If you want a custom combination, the configurator explains the available bases. The NH35 movement guide and the NH34 GMT movement guide cover the sister calibres, and the watch parts guides help with dials and hands.

FAQ

What is the difference between the NH36 and the NH35?

NH36 displays day and date; NH35 displays the date only. TMI lists the same main dimensions and performance figures, but the complete build and its calendar opening still need checking.

Can I fit an NH35 dial on an NH36 movement?

A date-only dial may hide the day display; it is not automatically unusable. Check dial feet, calendar alignment, clearance and the complete assembly. An NH35 cannot provide a working day display.

How accurate is the NH36?

TMI states static accuracy of −20 to +40 seconds per day under its measurement conditions. A tighter result after regulation requires evidence for the actual watch; it is not guaranteed by the calibre name.