diff --git a/cli/Cargo.toml b/cli/Cargo.toml
index 0f1b7ef8..6543e724 100644
--- a/cli/Cargo.toml
+++ b/cli/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "zhang"
-version = "0.1.0-alpha.4"
+version = "0.1.0-alpha.5"
 authors = ["Kilerd <blove694@gmail.com>"]
 description = "a plain text double-accounting tool which is compatible with beancount but more powerful"
 edition = "2018"
diff --git a/core/src/constants.rs b/core/src/constants.rs
index 9daee316..db5403f6 100644
--- a/core/src/constants.rs
+++ b/core/src/constants.rs
@@ -10,6 +10,7 @@ pub const DEFAULT_COMMODITY_PRECISION: i32 = 2;
 pub const DEFAULT_OPERATING_CURRENCY: &str = "CNY";
 pub const DEFAULT_ROUNDING: Rounding = Rounding::RoundDown;
 pub const DEFAULT_BALANCE_TOLERANCE_PRECISION: i32 = 2;
+pub const DEFAULT_TIMEZONE: &str = "Asia/Hong_Kong";
 
 pub const DEFAULT_ROUNDING_PLAIN: &str = "RoundDown";
 pub const DEFAULT_COMMODITY_PRECISION_PLAIN: &str = "2";
diff --git a/core/src/options.rs b/core/src/options.rs
index 1c9bf349..7ee957a5 100644
--- a/core/src/options.rs
+++ b/core/src/options.rs
@@ -1,12 +1,14 @@
 use itertools::Itertools;
-use log::{error, info};
+use log::{error, info, warn};
 use sqlx::SqliteConnection;
 use std::str::FromStr;
 use std::string::ToString;
 use strum::{AsRefStr, EnumIter, EnumString, IntoEnumIterator};
 use zhang_ast::{Directive, Options, Rounding, SpanInfo, Spanned, ZhangString};
 
-use crate::constants::{DEFAULT_BALANCE_TOLERANCE_PRECISION_PLAIN, DEFAULT_COMMODITY_PRECISION_PLAIN, DEFAULT_OPERATING_CURRENCY, DEFAULT_ROUNDING_PLAIN};
+use crate::constants::{
+    DEFAULT_BALANCE_TOLERANCE_PRECISION_PLAIN, DEFAULT_COMMODITY_PRECISION_PLAIN, DEFAULT_OPERATING_CURRENCY, DEFAULT_ROUNDING_PLAIN, DEFAULT_TIMEZONE,
+};
 use crate::ZhangResult;
 use chrono_tz::Tz;
 
@@ -36,9 +38,16 @@ impl BuiltinOption {
             BuiltinOption::DefaultBalanceTolerancePrecision => DEFAULT_BALANCE_TOLERANCE_PRECISION_PLAIN.to_owned(),
             BuiltinOption::DefaultCommodityPrecision => DEFAULT_COMMODITY_PRECISION_PLAIN.to_owned(),
             BuiltinOption::Timezone => {
-                let system_timezone = iana_time_zone::get_timezone().expect("cannot get the system timezone");
-                info!("detect system timezone is {}", system_timezone);
-                system_timezone
+                match iana_time_zone::get_timezone() {
+                    Ok(timezone) => {
+                        info!("detect system timezone is {}", timezone);
+                        timezone
+                    }
+                    Err(e) => {
+                        warn!("cannot get timezone, fall back to use GMT+8 as default timezone: {}", e);
+                        DEFAULT_TIMEZONE.to_owned()
+                    }
+                }
             }
         }
     }
diff --git a/core/src/utils/logging.rs b/core/src/utils/logging.rs
new file mode 100644
index 00000000..6b68cf37
--- /dev/null
+++ b/core/src/utils/logging.rs
@@ -0,0 +1,14 @@
+use log::warn;
+
+pub trait LoggingExit {
+    fn warn_if_none(self, msg: impl AsRef<str>) -> Self;
+}
+
+impl<T> LoggingExit for Option<T> {
+    fn warn_if_none(self, msg: impl AsRef<str>) -> Self {
+        if self.is_none() {
+            warn!("{}", msg.as_ref())
+        }
+        self
+    }
+}
diff --git a/core/src/utils/mod.rs b/core/src/utils/mod.rs
index 852d5297..93371900 100644
--- a/core/src/utils/mod.rs
+++ b/core/src/utils/mod.rs
@@ -7,6 +7,7 @@ pub mod hashmap;
 pub mod id;
 pub mod price_grip;
 pub mod string_;
+pub mod logging;
 
 pub fn has_path_visited<'a>(visited: impl IntoIterator<Item = &'a Pattern>, path: &Path) -> bool {
     visited.into_iter().any(|pattern| pattern.matches_path(path))