How can I solve day problem in appinsight alert? - azure

Question

I have a problem with my kusto query. this kusto query is running inside the alert call. I tried to send a notification to our client via email.
Scenario :
I am trying to send messages between 7 am and 13 am on Saturday. (only Saturday) But I am getting messages also Sunday. There is nothing here below the query. I think it is related to app insight alert.
requests
| extend Customer= trim_end('/', tostring(split(customDimensions.source, '//')[1]))
| extend alarmOK=iif(datetime_diff('minute', now(), timestamp) > 20, 1, 0)
| extend issaturday=iif(dayofweek(timestamp) == 6d, 1, 0)
| extend workinghour = hourofday(timestamp)
| extend
sendnotify1=iif(workinghour >= 7 and workinghour < 13, 1, 0),
sendnotify2=iif(hourofday(now()) >= 7 and hourofday(now()) < 13, 1, 0)
| extend alarmmessage = "alert message"
| where timestamp > ago(24h) and Customer == "mycustomer"
| where issaturday == 1
| where workinghour >= 7 and workinghour < 13
| top 1 by timestamp desc

Answer 1

All datetimes in Kusto are stored as UTC.
Use datetime_utc_to_local to get the timestamp in your local time zone, e.g.:
let timestamp = now();
print datetime_utc_to_local(timestamp, "Australia/Melbourne")
Fiddle
print_0
2023-01-10T21:10:08.0645922Z
P.S.
Your query could be simplified significantly.
KQL supports the Boolean data type (bool).
KQL supports datetime & timespan arithmetic.
Even if for some reason you wanted to add a column named issaturday and then filter by it, it could easily be done like this:
| extend issaturday = dayofweek(timestamp) == 6d | where issaturday
// Sample data generation. Not part of the solution.
let requests = materialize(
range i from 1 to 100 step 1
| extend timestamp = ago(7d * rand())
);
// Solution starts here
requests
| where dayofweek(timestamp) == 6d
and timestamp % 1d between (7h .. 13h)
and now() - timestamp > 20m
i
timestamp
5
2023-01-07T08:37:39.3449345Z
80
2023-01-07T09:07:36.4794478Z
83
2023-01-07T10:51:19.4051319Z
Fiddle