Apps Manager might not respect the day of the week when creating an autoscaler scheduled limit change

Products

• VMware Tanzu Application Service for VMs

Issue/Introduction

When create autoscaler scheduled a limit change on Apps Manager, it will convert the date / time (in local time) entered by the user to UTC time. In some time zones that are further off from UTC, it’s totally possible to be in a situation where the local time and UTC are different days, resulting in different days of the week. In such cases, Apps Manger doesn't convert the selected day of the week.

For example, 2021-02-05T05:00 UTC+8 is actually 2021-02-04T21:00:00, so it’s a Friday locally but a Thursday in UTC. 

Apps Manager will submit the local day of the week (Friday in this example), Autoscaler will see that the date submitted is not a Friday (2021-02-04 is a Thursday) and bump the date to be the next occurring Friday. In this example, it will bump the date to 2021-02-05. Consequently Apps Manager will show the scheduled time and date as 2021-02-06T05:00 UTC+8 Friday.
 

Environment

Product Version: 2.10

Resolution

The issue has been reported to the Apps Manager product team and they are working on a fix. There are also several workarounds available before a fix is released:
 

• Use the CF CLI plugin. It doesn’t adjust time zones, so the customer would just need to convert the target time to UTC & adjust the day of week on which it should reoccur.
• Use Apps Manager and put in your normal date & time, but pick the day of the week based on the UTC day of the week. Thursday if you want 2021-02-05T05:00 UTC+8, enter that date and time but for day of the week pick Thursday, because when you convert the local time to UTC, it’s Thursday not Friday. Since Autoscaler runs on UTC, you should end up with the right date and time coming back, i.e. Apps Manager should convert the result back and show you the right date.

For example, if you want to increase the number of instances of an app on every Tuesday (starting from 2nd Feb) at 05:00 AM (suppose this is in your local TZ UTC+8) to 4, then take of one the following options:
 

• Using CF CLI plugin: cf create-autoscaling-slc <app name> 2021-02-01T21:00:00Z 4 4 -r Mo
• On "Apps Manager" select 2021-02-02 05:00:00AM, but select Mo as Repeat day