Why does the object ‘date’ trigger ‘neither XDB connection nor function’ error in my function?

I’m encountering an error when defining a query function in DolphinDB. Here’s my scenario:

Table Definition:

dt = 2025.01.01T01:01:51.100 2025.01.02T01:01:51.000 2025.01.03T04:01:51.900
sym = ["IBM", "MSFTN", "GOOGS"]
value = 1..3
t = table(dt, sym, value)

Successful Direct Query:

day = "20250101"
date = temporalParse(day, "yyyyMMdd")
select * from t where date(dt) = date // Works correctly
/*
dt                  sym  value
2025.01.01T01:01:51.100 IBM  1
*/

Function Implementation (Causing Error):

def myFunc(day, t) {
    date = temporalParse(day, "yyyyMMdd")
    return select * from t where date(dt) == date
}

myFunc("20250101", t) // The object '2025.01.01' is neither a XDB connection nor a function definition. RefId: S06006

Error Details:

Error code S06006 indicates calling a non-callable object.

User manual confirms only functions/XDB connections are callable.

What I Tried:

Verified direct query works outside the function.

Confirmed temporalParse correctly returns a DATE type (e.g., 2025.01.01).

Checked for typos/syntax issues in the function.

Question: Why does the same logic fail when encapsulated in a function? How should I modify myFunc to avoid the non-callable object error?

Environment:

DolphinDB version: 3.00.2.4 2025.02.26 WIN_JIT x86_64

OS: win10