RE: Time Format 24 hours in Unified Interface
Hi Olegof,
I have tried on Online CRM and got no issue regarding the time format.
Could you please make sure that you have set the correct format (HH: mm) in the settings.
The steps to check is below:
1) Click on the Settings button in the top menu as shown in the screenshot below

2) Go to Personalization Settings

3) A new window will appear, go to the Format tab and click on Customization.

4) Again a window open, go to Time tab and check the Time format. If it is not set as HH: mm then choose from the dropdown list and save changes by clicking on the Apply button at the bottom of the page and then click Ok.

It will reload the page and now you can see the time format based on your selection.
Please mark my answer verified if it helps.
Warm Regards,
Kirti Singh | Soluzione IT Services.