diff --git a/Cargo.lock b/Cargo.lock
index 952a37d..4adae16 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,6 +2,21 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "android-tzdata"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e999941b234f3131b00bc13c22d06e8c5ff726d1b6318ac7eb276997bbb4fef0"
+
+[[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 = "anstream"
 version = "0.6.4"
@@ -50,6 +65,47 @@ dependencies = [
  "windows-sys",
 ]
 
+[[package]]
+name = "autocfg"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
+
+[[package]]
+name = "bumpalo"
+version = "3.14.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7f30e7476521f6f8af1a1c4c0b8cc94f0bee37d91763d0ca2665f299b6cd8aec"
+
+[[package]]
+name = "cc"
+version = "1.0.83"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f1174fb0b6ec23863f8b971027804a42614e347eafb0a95bf0b12cdae21fc4d0"
+dependencies = [
+ "libc",
+]
+
+[[package]]
+name = "cfg-if"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+
+[[package]]
+name = "chrono"
+version = "0.4.31"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7f2c685bad3eb3d45a01354cedb7d5faa66194d1d58ba6e267a8de788f79db38"
+dependencies = [
+ "android-tzdata",
+ "iana-time-zone",
+ "js-sys",
+ "num-traits",
+ "wasm-bindgen",
+ "windows-targets",
+]
+
 [[package]]
 name = "clap"
 version = "4.4.8"
@@ -96,6 +152,12 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "acbf1af155f9b9ef647e42cdc158db4b64a1b61f743629225fde6f3e0be2a7c7"
 
+[[package]]
+name = "core-foundation-sys"
+version = "0.8.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e496a50fda8aacccc86d7529e2c1e0892dbd0f898a6b5645b5561b89c3210efa"
+
 [[package]]
 name = "equivalent"
 version = "1.0.1"
@@ -114,6 +176,29 @@ version = "0.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "95505c38b4572b2d910cecb0281560f54b440a19336cbbcb27bf6ce6adc6f5a8"
 
+[[package]]
+name = "iana-time-zone"
+version = "0.1.58"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8326b86b6cff230b97d0d312a6c40a60726df3332e721f72a1b035f451663b20"
+dependencies = [
+ "android_system_properties",
+ "core-foundation-sys",
+ "iana-time-zone-haiku",
+ "js-sys",
+ "wasm-bindgen",
+ "windows-core",
+]
+
+[[package]]
+name = "iana-time-zone-haiku"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f31827a206f56af32e590ba56d5d2d085f558508192593743f16b2306495269f"
+dependencies = [
+ "cc",
+]
+
 [[package]]
 name = "indexmap"
 version = "2.1.0"
@@ -130,6 +215,42 @@ version = "1.0.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "af150ab688ff2122fcef229be89cb50dd66af9e01a4ff320cc137eecc9bacc38"
 
+[[package]]
+name = "js-sys"
+version = "0.3.66"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cee9c64da59eae3b50095c18d3e74f8b73c0b86d2792824ff01bbce68ba229ca"
+dependencies = [
+ "wasm-bindgen",
+]
+
+[[package]]
+name = "libc"
+version = "0.2.150"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "89d92a4743f9a61002fae18374ed11e7973f530cb3a3255fb354818118b2203c"
+
+[[package]]
+name = "log"
+version = "0.4.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b5e6163cb8c49088c2c36f57875e58ccd8c87c7427f7fbd50ea6710b2f3f2e8f"
+
+[[package]]
+name = "num-traits"
+version = "0.2.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "39e3200413f237f41ab11ad6d161bc7239c84dcb631773ccd7de3dfe4b5c267c"
+dependencies = [
+ "autocfg",
+]
+
+[[package]]
+name = "once_cell"
+version = "1.18.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dd8b5dd2ae5ed71462c540258bedcb51965123ad7e7ccf4b9a8cafaa4a63576d"
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.70"
@@ -208,6 +329,7 @@ dependencies = [
 name = "tsheet-cli"
 version = "0.1.0"
 dependencies = [
+ "chrono",
  "clap",
  "serde",
  "serde_yaml",
@@ -231,6 +353,69 @@ version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "711b9620af191e0cdc7468a8d14e709c3dcdb115b36f838e601583af800a370a"
 
+[[package]]
+name = "wasm-bindgen"
+version = "0.2.89"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0ed0d4f68a3015cc185aff4db9506a015f4b96f95303897bfa23f846db54064e"
+dependencies = [
+ "cfg-if",
+ "wasm-bindgen-macro",
+]
+
+[[package]]
+name = "wasm-bindgen-backend"
+version = "0.2.89"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1b56f625e64f3a1084ded111c4d5f477df9f8c92df113852fa5a374dbda78826"
+dependencies = [
+ "bumpalo",
+ "log",
+ "once_cell",
+ "proc-macro2",
+ "quote",
+ "syn",
+ "wasm-bindgen-shared",
+]
+
+[[package]]
+name = "wasm-bindgen-macro"
+version = "0.2.89"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0162dbf37223cd2afce98f3d0785506dcb8d266223983e4b5b525859e6e182b2"
+dependencies = [
+ "quote",
+ "wasm-bindgen-macro-support",
+]
+
+[[package]]
+name = "wasm-bindgen-macro-support"
+version = "0.2.89"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f0eb82fcb7930ae6219a7ecfd55b217f5f0893484b7a13022ebb2b2bf20b5283"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+ "wasm-bindgen-backend",
+ "wasm-bindgen-shared",
+]
+
+[[package]]
+name = "wasm-bindgen-shared"
+version = "0.2.89"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7ab9b36309365056cd639da3134bf87fa8f3d86008abf99e612384a6eecd459f"
+
+[[package]]
+name = "windows-core"
+version = "0.51.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f1f8cf84f35d2db49a46868f947758c7a1138116f7fac3bc844f43ade1292e64"
+dependencies = [
+ "windows-targets",
+]
+
 [[package]]
 name = "windows-sys"
 version = "0.48.0"
diff --git a/Cargo.toml b/Cargo.toml
index b3b0dff..f35f8ba 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -6,6 +6,7 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+chrono = "0.4.31"
 clap = { version = "4.4.8", features = ["derive"] }
 serde = { version = "1.0.193", features = ["derive"] }
 serde_yaml = "0.9.27"
diff --git a/src/main.rs b/src/main.rs
index f8bd37d..75d9a58 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -4,7 +4,7 @@ use std::fs::File;
 use std::time::{SystemTime, UNIX_EPOCH, Duration};
 use std::ops::{Add, Sub};
 use clap::Parser;
-use std::collections::HashMap;
+use chrono::DateTime;
 
 #[derive(Debug, Parser)]
 struct Flags {
@@ -48,27 +48,42 @@ fn add(f: &String, x: &Option<String>, tag: &Option<String>) -> Result<(), Strin
    Ok(())
 }
 
-#[derive(Debug, Serialize)]
+#[derive(Debug, Serialize, Clone)]
 struct Log {
    t: String,
-   d: u8,
    xs: Vec<LogX>,
 }
-#[derive(Debug, Serialize)]
+#[derive(Debug, Serialize, Clone)]
 struct LogX {
    d: u8,
    x: String,
-   xs: Vec<String>,
 }
 
 fn log(f: &String, since: &Option<String>) -> Result<(), String> {
    let since = parse_time(since)?;
    let tsheet = load(&f)?;
    let tsheet = tsheet.since(since);
-   let mut logs = HashMap::new();
-   for &x in &tsheet.xs {
+   let tsheet = tsheet.sorted();
+
+   let mut result = vec![];
+   let mut curr = Log{t: "".to_string(), xs: vec![]};
+   for x in &tsheet.xs {
+      if curr.t != x.timestamp() {
+         if curr.xs.len() > 0 {
+            result.push(curr.clone());
+         }
+         curr.xs.truncate(0);
+         curr.t = x.timestamp();
+      }
+      curr.t = x.timestamp();
+      curr.xs.push(LogX{d: 0, x: x.x.clone()});
    }
-   println!("{:?}", logs);
+   if curr.xs.len() > 0 {
+      result.push(curr.clone());
+   }
+
+   println!("{}", serde_yaml::to_string(&result).unwrap());
+
    Err("not impl".to_string())
 }
 
@@ -86,7 +101,7 @@ struct TSheet {
    xs: Vec<X>,
 }
 
-#[derive(Debug, PartialEq, Serialize, Deserialize, Clone)]
+#[derive(Debug, PartialEq, Serialize, Deserialize, Clone, Ord, Eq, PartialOrd)]
 struct X {
    t: i64,
    x: String,
@@ -165,12 +180,23 @@ impl TSheet {
    fn add(&mut self, x: String, tag: String) {
       self.xs.push(new_x(SystemTime::now(), x, tag));
    }
+
+   fn sorted(&self) -> TSheet {
+      let mut result = TSheet{xs: self.xs.clone()};
+      result.xs.sort();
+      return result;
+   }
 }
 
 impl X {
    fn ts(&self) -> SystemTime {
       UNIX_EPOCH.add(Duration::from_secs(self.t.try_into().unwrap()))
    }
+
+   fn timestamp(&self) -> String {
+      let dt = DateTime::from_timestamp(self.t, 0).unwrap();
+      dt.format("%Y-%m-%d").to_string()
+   }
 }
 
 fn new_x(t: SystemTime, x: String, tag: String) -> X {