Hello everyone,
Recently purchased a Seiko 7A38-706A and I noticed the day and date change around 9/10 pm.
Not familiar with these models so not sure if this is expected (I have another vintage Seiko and this also happens).
Is this normal? Can be serviced or it's a permanent defect that happens after changing the date between 9PM and 3AM.
Thanks.
Seiko 7A38-706A date changes early
Re: Seiko 7A38-706A date changes early
Hello and welcome to the forum.
I'll use your question as an opportunity to link this sticky thread from the old archived forum:
Sticky: How to set the Day / Date on a Seiko 7A38 - and when NOT to do it
This is the quote I was looking for:
Yours is not a manufacturing fault. It was likely caused by someone pulling the hands (for a service, or whatever reason) and then not taking care to re-set them in the correct positions (relative to the position of the changeover wheel) when re-fitting. It is unlikely to have been caused by someone carelessly setting the day / date between 9:00 pm and 3:00 am. That usually causes permanent damage to the plastic changeover wheel (stripped teeth or broken lever arms).
The solution is to get a watchmaker to pull the central hand stack and re-set them correctly.
I'll use your question as an opportunity to link this sticky thread from the old archived forum:
Sticky: How to set the Day / Date on a Seiko 7A38 - and when NOT to do it
This is the quote I was looking for:
I have a couple of watches which change the date dead on Midnight, but from memory, they start the changeover cycle slightly earlier, around 10.45 pm. I've also had watches come into my possession, which started the changeover early (like yours) and very late (like 4:30 in the morning).Whenever I've observed them, the day / date changeover sequence of my 7A38's goes as follows:
11:00 PM Date wheel starts to move and is usually completed by 00:30 AM (the following day).
01:00 AM (previous) Day starts to move. By 01:30 AM changed to 'alternate' language; by 02:30 AM the Day changeover is complete.
Yours is not a manufacturing fault. It was likely caused by someone pulling the hands (for a service, or whatever reason) and then not taking care to re-set them in the correct positions (relative to the position of the changeover wheel) when re-fitting. It is unlikely to have been caused by someone carelessly setting the day / date between 9:00 pm and 3:00 am. That usually causes permanent damage to the plastic changeover wheel (stripped teeth or broken lever arms).
The solution is to get a watchmaker to pull the central hand stack and re-set them correctly.
Re: Seiko 7A38-706A date changes early
Thanks for the reply.
It's possible the hands haven't been placed correctly as you mention, because the chronograph sweep hand is bent at the top, so someone definitely messed around. The tip is well aligned but not the rest of the hand.
Do you know where can I find parts or the parts numbers for this chrono sweep hand?
As for the alignment, does it 'simply' work by removing the minutes & hour hand, turn the crown until the date changes and then place the hands at 12 o'clock? Or it's more complex that this?
It's possible the hands haven't been placed correctly as you mention, because the chronograph sweep hand is bent at the top, so someone definitely messed around. The tip is well aligned but not the rest of the hand.
Do you know where can I find parts or the parts numbers for this chrono sweep hand?
As for the alignment, does it 'simply' work by removing the minutes & hour hand, turn the crown until the date changes and then place the hands at 12 o'clock? Or it's more complex that this?
Re: Seiko 7A38-706A date changes early
The Seiko part number for the 7A38-706A sweep second hand is 13SC06LG, though I'm not sure where you'll find one. Your hand doesn't look too bad. I'm sure the tip could be carefully straightened.
Yes, correct day / date alignment is achieved as simply as that, although perfectly aligning the hour and minute hand with the twelve o'clock baton comes with practice. To ensure that the hour and minute hand are correctly aligned with respect to each other, after I've fitted them, I habitually wind the watch forward to 6:00 - checking that the two hands are in a perfect straight line. That way you can be sure that the hour hand points to its baton at every 'o'clock'.
Yes, correct day / date alignment is achieved as simply as that, although perfectly aligning the hour and minute hand with the twelve o'clock baton comes with practice. To ensure that the hour and minute hand are correctly aligned with respect to each other, after I've fitted them, I habitually wind the watch forward to 6:00 - checking that the two hands are in a perfect straight line. That way you can be sure that the hour hand points to its baton at every 'o'clock'.
Re: Seiko 7A38-706A date changes early
Actually Cousins UK have them in stock. Price is £4.95 + VAT.
Re: Seiko 7A38-706A date changes early
Thank you for letting me know!Seiko7A38 wrote: ↑Tue Jun 24, 2025 6:09 pmActually Cousins UK have them in stock. Price is £4.95 + VAT.
The photo doesn't quite match the hand I have on my watch, as it doesn't have the 'circle' at the top end. I assume it's just a placeholder photo on that website or?
Re: Seiko 7A38-706A date changes early
No, you're supposed to trim that off - that's how NOS Seiko hands come. 
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doing_time
- Posts: 22
- Joined: Sat Apr 12, 2025 11:36 am
- Location: Ireland
Re: Seiko 7A38-706A date changes early
OP, if you drop the watch to someone to refit the hands he should be able to tweek the chrono seconds hand straight. Still and all having a nos one at the ready at such a low price would be a no brainer.
If you were in this side of the pond I'd gladly do the job for you. Any half competent modder or watchmaker can do that.
If you were in this side of the pond I'd gladly do the job for you. Any half competent modder or watchmaker can do that.
Re: Seiko 7A38-706A date changes early
I wrote that because I remembered having to do it myself once, many years ago. I bought a Racer J39027-70 off eBay Germany in November 2013. It needed a little TLC / good cleaning and restoration. The worst part was the was badly scratched crystal, but when I withdrew the dial / movement, I found the tip of the sweep second hand was slightly bent. I massaged it back into alignment, in situ, between two pieces of pegwood. I thought I'd posted these photos in the Racer 'Spanish 7A38 Inquisition' thread, on the old forum, but I couldn't find them. So here they are, belatedly ....
- rsz_p1220014.jpg (238.78 KiB) Viewed 7227 times
- rsz_p1220103.jpg (241.74 KiB) Viewed 7227 times
- rsz_p1220104.jpg (244.01 KiB) Viewed 7227 times
- rsz_p1220105.jpg (242.1 KiB) Viewed 7227 times
Re: Seiko 7A38-706A date changes early
@Seiko7A38: Wow, thanks a lot for all the help and details! Super useful!
Re: Seiko 7A38-706A date changes early
I'm in center Europe but I'll try to find someone for the date adjustment.doing_time wrote: ↑Mon Jun 30, 2025 11:54 am OP, if you drop the watch to someone to refit the hands he should be able to tweek the chrono seconds hand straight. Still and all having a nos one at the ready at such a low price would be a no brainer.
If you were in this side of the pond I'd gladly do the job for you. Any half competent modder or watchmaker can do that.
As for the chrono hand, I'll try to straighten it out myself first. If not, I'll get the one Seiko7A38 linked. It's just that shipping and taxes it come out to over 20€
