Set default timezone in metrics command based on system settings

Cargo.toml

@@ -16,6 +16,7 @@ arrow-ipc = { version = "=58.1.0", features = ["lz4"] }
 clap = { version = "4", features = ["derive", "env"] }
 dirs = "6"
 duckdb = { version = "=1.10501.0", features = ["bundled", "appender-arrow"] }
+iana-time-zone = "0.1"
 open = "5"
 regex = "1"
 serde = { version = "1", features = ["derive"] }

skills/apitally-cli/references/commands.md

@@ -99,7 +99,7 @@ Fetch aggregated metrics for an app. Outputs NDJSON to stdout by default.
 - `--interval`: Time interval for grouping (`month`, `day`, `hour`, `minute`). When omitted, returns a single row per group for the entire time range
 - `--group-by`: JSON array of field names to group by, in addition to time period
 - `--filters`: JSON array of filter objects (see below)
-- `--timezone`: Timezone for intervals and to interpret since/until if not tz-aware (defaults to UTC)
+- `--timezone`: Timezone for intervals and to interpret since/until if not tz-aware (defaults to system timezone)
 - `--db`: Write to `metrics` table in DuckDB instead of outputting NDJSON to stdout
 
 **Deduplication in DuckDB:** Deletes all existing rows for the same `app_id` within the fetched time range before inserting new data.

src/main.rs

@@ -183,7 +183,7 @@ enum Command {
 
         /// Timezone for intervals and to interpret since/until if not tz-aware
         ///
-        /// Defaults to UTC. Example: America/New_York.
+        /// Defaults to system timezone. Example: America/New_York.
         #[arg(long)]
         timezone: Option<String>,
 

src/metrics.rs

@@ -77,9 +77,11 @@ pub fn run(
             .map_err(|e| input_err(format!("invalid JSON for --filters: {e}")))?;
         body["filters"] = filters_value;
     }
-    if let Some(timezone) = timezone {
-        body["timezone"] = serde_json::json!(timezone);
-    }
+    let timezone = match timezone {
+        Some(tz) => tz.to_owned(),
+        None => iana_time_zone::get_timezone().unwrap_or_else(|_| "UTC".to_owned()),
+    };
+    body["timezone"] = serde_json::json!(timezone);
     let url = format!("{api_base_url}/v1/apps/{app_id}/metrics");
     let response = api_post(&url, &api_key, &body)?;
 
@@ -229,7 +231,7 @@ mod tests {
             Some("hour"),
             Some(r#"["method"]"#),
             None,
-            None,
+            Some("Australia/Brisbane"),
             None,
             Some("test-key"),
             Some(&server.url()),