We conduct regular maintenance every three months that involves service downtime.
Please check the following page for details.
▼ [Updated regularly] Overview and schedule of regular maintenance
https://help.teachme.jp/hc/en-us/articles/51961436086809
Related:
How are notifications sent when new features, updates, or maintenance are implemented?
https://help.teachme.jp/hc/en-us/articles/6478511346073
Can I change the email address for contract renewals and maintenance notifications?
https://help.teachme.jp/hc/en-us/articles/900005508066