support customized timezone for clock

Cargo.lock

@@ -11,6 +11,15 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "android_system_properties"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "819e7219dbd41043ac279b19830f2efc897156490d7fd6ea916720117ee66311"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "atty"
 version = "0.2.14"
@@ -34,6 +43,12 @@ version = "1.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
 
+[[package]]
+name = "bumpalo"
+version = "3.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c1ad822118d20d2c234f427000d5acc36eabe1e29a348c89b63dd60b13f28e5d"
+
 [[package]]
 name = "cassowary"
 version = "0.3.0"
@@ -48,17 +63,42 @@ checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
 [[package]]
 name = "chrono"
-version = "0.4.19"
+version = "0.4.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "670ad68c9088c2a963aaa298cb369688cf3f9465ce5e2d4ca10e6e0098a1ce73"
+checksum = "bfd4d1b31faaa3a89d7934dbded3111da0d2ef28e3ebccdb4f0179f5929d1ef1"
 dependencies = [
- "libc",
+ "iana-time-zone",
+ "js-sys",
  "num-integer",
  "num-traits",
  "time",
+ "wasm-bindgen",
  "winapi",
 ]
 
+[[package]]
+name = "chrono-tz"
+version = "0.6.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "29c39203181991a7dd4343b8005bd804e7a9a37afb8ac070e43771e8c820bbde"
+dependencies = [
+ "chrono",
+ "chrono-tz-build",
+ "phf",
+ "serde",
+]
+
+[[package]]
+name = "chrono-tz-build"
+version = "0.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6f509c3a87b33437b05e2458750a0700e5bdd6956176773e6c7d6dd15a283a0c"
+dependencies = [
+ "parse-zoneinfo",
+ "phf",
+ "phf_codegen",
+]
+
 [[package]]
 name = "clap"
 version = "3.2.12"
@@ -103,12 +143,19 @@ name = "clock-tui"
 version = "0.4.0"
 dependencies = [
  "chrono",
+ "chrono-tz",
  "clap",
  "crossterm 0.24.0",
  "regex",
  "tui",
 ]
 
+[[package]]
+name = "core-foundation-sys"
+version = "0.8.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5827cebf4670468b8772dd191856768aedcb1b0278a04f989f7766351917b9dc"
+
 [[package]]
 name = "crossterm"
 version = "0.23.2"
@@ -171,6 +218,19 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "iana-time-zone"
+version = "0.1.46"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ad2bfd338099682614d3ee3fe0cd72e0b6a41ca6a87f6a74a3bd593c91650501"
+dependencies = [
+ "android_system_properties",
+ "core-foundation-sys",
+ "js-sys",
+ "wasm-bindgen",
+ "winapi",
+]
+
 [[package]]
 name = "indexmap"
 version = "1.9.1"
@@ -181,6 +241,15 @@ dependencies = [
  "hashbrown",
 ]
 
+[[package]]
+name = "js-sys"
+version = "0.3.59"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "258451ab10b34f8af53416d1fdab72c22e805f0c92a1136d59470ec0b11138b2"
+dependencies = [
+ "wasm-bindgen",
+]
+
 [[package]]
 name = "libc"
 version = "0.2.126"
@@ -278,6 +347,54 @@ dependencies = [
  "windows-sys",
 ]
 
+[[package]]
+name = "parse-zoneinfo"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c705f256449c60da65e11ff6626e0c16a0a0b96aaa348de61376b249bc340f41"
+dependencies = [
+ "regex",
+]
+
+[[package]]
+name = "phf"
+version = "0.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "928c6535de93548188ef63bb7c4036bd415cd8f36ad25af44b9789b2ee72a48c"
+dependencies = [
+ "phf_shared",
+]
+
+[[package]]
+name = "phf_codegen"
+version = "0.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a56ac890c5e3ca598bbdeaa99964edb5b0258a583a9eb6ef4e89fc85d9224770"
+dependencies = [
+ "phf_generator",
+ "phf_shared",
+]
+
+[[package]]
+name = "phf_generator"
+version = "0.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b1181c94580fa345f50f19d738aaa39c0ed30a600d95cb2d3e23f94266f14fbf"
+dependencies = [
+ "phf_shared",
+ "rand",
+]
+
+[[package]]
+name = "phf_shared"
+version = "0.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e1fb5f6f826b772a8d4c0394209441e7d37cbbb967ae9c7e0e8134365c9ee676"
+dependencies = [
+ "siphasher",
+ "uncased",
+]
+
 [[package]]
 name = "proc-macro-error"
 version = "1.0.4"
@@ -320,6 +437,21 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "rand"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404"
+dependencies = [
+ "rand_core",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.6.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d34f1408f55294453790c48b2f1ebbb1c5b4b7563eb1f418bcfcfdbb06ebb4e7"
+
 [[package]]
 name = "redox_syscall"
 version = "0.2.13"
@@ -352,6 +484,12 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
 
+[[package]]
+name = "serde"
+version = "1.0.144"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0f747710de3dcd43b88c9168773254e809d8ddbdf9653b84e2554ab219f17860"
+
 [[package]]
 name = "signal-hook"
 version = "0.3.14"
@@ -382,6 +520,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "siphasher"
+version = "0.3.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7bd3e3206899af3f8b12af284fafc038cc1dc2b41d1b89dd17297221c5d225de"
+
 [[package]]
 name = "smallvec"
 version = "1.9.0"
@@ -444,6 +588,15 @@ dependencies = [
  "unicode-width",
 ]
 
+[[package]]
+name = "uncased"
+version = "0.9.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "09b01702b0fd0b3fadcf98e098780badda8742d4f4a7676615cad90e8ac73622"
+dependencies = [
+ "version_check",
+]
+
 [[package]]
 name = "unicode-ident"
 version = "1.0.2"
@@ -480,6 +633,60 @@ version = "0.11.0+wasi-snapshot-preview1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
 
+[[package]]
+name = "wasm-bindgen"
+version = "0.2.82"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fc7652e3f6c4706c8d9cd54832c4a4ccb9b5336e2c3bd154d5cccfbf1c1f5f7d"
+dependencies = [
+ "cfg-if",
+ "wasm-bindgen-macro",
+]
+
+[[package]]
+name = "wasm-bindgen-backend"
+version = "0.2.82"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "662cd44805586bd52971b9586b1df85cdbbd9112e4ef4d8f41559c334dc6ac3f"
+dependencies = [
+ "bumpalo",
+ "log",
+ "once_cell",
+ "proc-macro2",
+ "quote",
+ "syn",
+ "wasm-bindgen-shared",
+]
+
+[[package]]
+name = "wasm-bindgen-macro"
+version = "0.2.82"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b260f13d3012071dfb1512849c033b1925038373aea48ced3012c09df952c602"
+dependencies = [
+ "quote",
+ "wasm-bindgen-macro-support",
+]
+
+[[package]]
+name = "wasm-bindgen-macro-support"
+version = "0.2.82"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5be8e654bdd9b79216c2929ab90721aa82faf65c48cdf08bdc4e7f51357b80da"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+ "wasm-bindgen-backend",
+ "wasm-bindgen-shared",
+]
+
+[[package]]
+name = "wasm-bindgen-shared"
+version = "0.2.82"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6598dd0bd3c7d51095ff6531a5b23e02acdc81804e30d8f07afb77b7215a140a"
+
 [[package]]
 name = "winapi"
 version = "0.3.9"

Cargo.toml

@@ -17,6 +17,7 @@ crossterm = "0.24"
 chrono = "0.4"
 clap = { version = "3.2.12", features = ["derive"] }
 regex = "1.6.0"
+chrono-tz = { version = "0.6.3", features = ["serde"] }
 
 [[bin]]
 bench = false

src/app.rs

@@ -5,6 +5,7 @@ use chrono::NaiveDate;
 use chrono::NaiveDateTime;
 use chrono::NaiveTime;
 use chrono::TimeZone;
+use chrono_tz::Tz;
 use clap::Subcommand;
 use crossterm::event::KeyCode;
 use regex::Regex;
@@ -25,6 +26,9 @@ pub(crate) mod modes;
 pub(crate) enum Mode {
     /// The clock mode displays the current time, the default mode.
     Clock {
+        /// Custome timezone, for example "America/New_York", use local timezone if not specificed
+        #[clap(short = 'z', long, value_parser=parse_timezone)]
+        timezone: Option<Tz>,
         /// Do not show date
         #[clap(short = 'D', long, takes_value = false)]
         no_date: bool,
@@ -127,12 +131,14 @@ impl App {
             no_date: false,
             millis: false,
             no_seconds: false,
+            timezone: None,
         });
         match mode {
             Mode::Clock {
                 no_date,
                 no_seconds,
                 millis,
+                timezone,
             } => {
                 self.clock = Some(Clock {
                     size: self.size,
@@ -140,6 +146,7 @@ impl App {
                     show_date: !no_date,
                     show_millis: *millis,
                     show_secs: !no_seconds,
+                    timezone: *timezone,
                 });
             }
             Mode::Timer {
@@ -302,3 +309,7 @@ fn parse_datetime(s: &str) -> Result<DateTime<Local>, String> {
 
     Err("Invalid time format".to_string())
 }
+
+fn parse_timezone(s: &str) -> Result<Tz, String> {
+    s.parse()
+}

src/app/modes/clock.rs

@@ -1,4 +1,5 @@
-use chrono::Local;
+use chrono::{Local, Utc};
+use chrono_tz::Tz;
 use clock_tui::bricks_text::BricksText;
 use tui::{layout::Rect, style::Style, widgets::Widget};
 
@@ -10,24 +11,33 @@ pub(crate) struct Clock {
     pub show_date: bool,
     pub show_millis: bool,
     pub show_secs: bool,
+    pub timezone: Option<Tz>,
 }
 
 impl Widget for &Clock {
     fn render(self, area: Rect, buf: &mut tui::buffer::Buffer) {
-        let now = Local::now();
+        let now = if let Some(ref tz) = self.timezone {
-        let time_str = if self.show_millis {
+            Utc::now().with_timezone(tz).naive_local()
-            let mut str = now.format("%H:%M:%S%.3f").to_string();
-            str.truncate(str.len() - 2);
-            str
-        } else if self.show_secs {
-            now.format("%H:%M:%S").to_string()
         } else {
-            now.format("%H:%M").to_string()
+            Local::now().naive_local()
+        };
+        let mut time_str = now.format("%H:%M:%S%.3f").to_string();
+        if self.show_millis {
+            time_str.truncate(time_str.len() - 2);
+        } else if self.show_secs {
+            time_str.truncate(time_str.len() - 4);
+        } else {
+            time_str.truncate(time_str.len() - 7);
         };
         let time_str = time_str.as_str();
         let text = BricksText::new(time_str, self.size, self.size, self.style);
         let header = if self.show_date {
-            Some(now.format("%Y-%m-%d %Z").to_string())
+            let mut title = now.format("%Y-%m-%d").to_string();
+            if let Some(tz) = self.timezone {
+                title.push(' ');
+                title.push_str(tz.name());
+            }
+            Some(title)
         } else {
             None
         };