diff --git a/autotodo/Cargo.lock b/autotodo/Cargo.lock
index bd73bed..e6a08ed 100644
--- a/autotodo/Cargo.lock
+++ b/autotodo/Cargo.lock
@@ -11,6 +11,56 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "anstream"
+version = "0.6.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "43d5b281e737544384e969a5ccad3f1cdd24b48086a0fc1b2a5262a26b8f4f4a"
+dependencies = [
+ "anstyle",
+ "anstyle-parse",
+ "anstyle-query",
+ "anstyle-wincon",
+ "colorchoice",
+ "is_terminal_polyfill",
+ "utf8parse",
+]
+
+[[package]]
+name = "anstyle"
+version = "1.0.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5192cca8006f1fd4f7237516f40fa183bb07f8fbdfedaa0036de5ea9b0b45e78"
+
+[[package]]
+name = "anstyle-parse"
+version = "0.2.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4e7644824f0aa2c7b9384579234ef10eb7efb6a0deb83f9630a49594dd9c15c2"
+dependencies = [
+ "utf8parse",
+]
+
+[[package]]
+name = "anstyle-query"
+version = "1.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "40c48f72fd53cd289104fc64099abca73db4166ad86ea0b4341abe65af83dadc"
+dependencies = [
+ "windows-sys",
+]
+
+[[package]]
+name = "anstyle-wincon"
+version = "3.0.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "291e6a250ff86cd4a820112fb8898808a366d8f9f58ce16d1f538353ad55747d"
+dependencies = [
+ "anstyle",
+ "once_cell_polyfill",
+ "windows-sys",
+]
+
 [[package]]
 name = "autocfg"
 version = "1.5.0"
@@ -22,6 +72,8 @@ name = "autotodo"
 version = "0.1.0"
 dependencies = [
  "chrono",
+ "clap",
+ "env",
  "ron",
  "serde",
 ]
@@ -71,18 +123,79 @@ dependencies = [
  "windows-link",
 ]
 
+[[package]]
+name = "clap"
+version = "4.5.54"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c6e6ff9dcd79cff5cd969a17a545d79e84ab086e444102a591e288a8aa3ce394"
+dependencies = [
+ "clap_builder",
+ "clap_derive",
+]
+
+[[package]]
+name = "clap_builder"
+version = "4.5.54"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fa42cf4d2b7a41bc8f663a7cab4031ebafa1bf3875705bfaf8466dc60ab52c00"
+dependencies = [
+ "anstream",
+ "anstyle",
+ "clap_lex",
+ "strsim",
+]
+
+[[package]]
+name = "clap_derive"
+version = "4.5.49"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2a0b5487afeab2deb2ff4e03a807ad1a03ac532ff5a2cee5d86884440c7f7671"
+dependencies = [
+ "heck",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "clap_lex"
+version = "0.7.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c3e64b0cc0439b12df2fa678eae89a1c56a529fd067a9115f7827f1fffd22b32"
+
+[[package]]
+name = "colorchoice"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b05b61dc5112cbb17e4b6cd61790d9845d13888356391624cbe7e41efeac1e75"
+
 [[package]]
 name = "core-foundation-sys"
 version = "0.8.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "773648b94d0e5d620f64f280777445740e61fe701025087ec8b57f45c791888b"
 
+[[package]]
+name = "env"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bc95de49ad098572c02d3fbf368c9a020bfff5ae78483685b77f51d8a7e9486d"
+dependencies = [
+ "num_threads",
+]
+
 [[package]]
 name = "find-msvc-tools"
 version = "0.1.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8591b0bcc8a98a64310a2fae1bb3e9b8564dd10e381e6e28010fde8e8e8568db"
 
+[[package]]
+name = "heck"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
+
 [[package]]
 name = "iana-time-zone"
 version = "0.1.64"
@@ -107,6 +220,12 @@ dependencies = [
  "cc",
 ]
 
+[[package]]
+name = "is_terminal_polyfill"
+version = "1.70.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a6cb138bb79a146c1bd460005623e142ef0181e3d0219cb493e02f7d08a35695"
+
 [[package]]
 name = "js-sys"
 version = "0.3.85"
@@ -138,12 +257,27 @@ dependencies = [
  "autocfg",
 ]
 
+[[package]]
+name = "num_threads"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5c7398b9c8b70908f6371f47ed36737907c87c52af34c268fed0bf0ceb92ead9"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "once_cell"
 version = "1.21.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "42f5e15c9953c5e4ccceeb2e7382a716482c34515315f7b03532b8b4e8393d2d"
 
+[[package]]
+name = "once_cell_polyfill"
+version = "1.70.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "384b8ab6d37215f3c5301a95a4accb5d64aa607f1fcb26a11b5303878451b4fe"
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.106"
@@ -218,6 +352,12 @@ version = "1.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
 
+[[package]]
+name = "strsim"
+version = "0.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
+
 [[package]]
 name = "syn"
 version = "2.0.114"
@@ -241,6 +381,12 @@ version = "1.0.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9312f7c4f6ff9069b165498234ce8be658059c6728633667c526e27dc2cf1df5"
 
+[[package]]
+name = "utf8parse"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"
+
 [[package]]
 name = "wasm-bindgen"
 version = "0.2.108"
@@ -344,3 +490,12 @@ checksum = "7837d08f69c77cf6b07689544538e017c1bfcf57e34b4c0ff58e6c2cd3b37091"
 dependencies = [
  "windows-link",
 ]
+
+[[package]]
+name = "windows-sys"
+version = "0.61.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ae137229bcbd6cdf0f7b80a31df61766145077ddf49416a728b02cb3921ff3fc"
+dependencies = [
+ "windows-link",
+]
diff --git a/autotodo/Cargo.toml b/autotodo/Cargo.toml
index b5cb6ea..0fe12c3 100644
--- a/autotodo/Cargo.toml
+++ b/autotodo/Cargo.toml
@@ -5,5 +5,7 @@ edition = "2024"
 
 [dependencies]
 chrono = { version = "0.4.43", features = ["serde"] }
+clap = { version = "4.5.54", features = ["derive"] }
+env = "1.0.1"
 ron = "0.12.0"
 serde = { version = "1.0.228", features = ["derive"] }
diff --git a/autotodo/data/notes.md b/autotodo/data/notes.md
new file mode 100644
index 0000000..ab65c67
--- /dev/null
+++ b/autotodo/data/notes.md
@@ -0,0 +1,32 @@
+i: into issue
+d: someone else did it / took "assignment" (spiritual or actually in Gitea)
+r: tried unsucessfully, have to retry
+m: moved to a later, specified time
+c: i will come back to this when i feel like it, but no need to track it now
+p: Made progress, but not done
+n: no (catchall for not doing it)
+
+
+# 2026-01-20
+
+- [ ] Test 1
+- [ ] Test 2
+- [x] Test 3
+- [ ] Test 4
+- [ ] Test 5
+
+# 2026-01-21
+
+- [x] Test 1
+- [ ] Test 2
+- [ ] Test 6
+- [ ] Test 7
+
+# 2026-01-22
+
+- [ ] Test 1
+- [ ] Test 2
+- [ ] Test 4
+- [ ] Test 5
+- [ ] Test 6
+- [ ] Test 7
diff --git a/autotodo/src/main.rs b/autotodo/src/main.rs
index aa9668a..5b2918c 100644
--- a/autotodo/src/main.rs
+++ b/autotodo/src/main.rs
@@ -1,33 +1,120 @@
-use std::fs;
-use ron;
-use serde::{Serialize, Deserialize};
-use chrono;
+use chrono::{self, NaiveDate, Local};
+use clap::Parser;
+use serde::{Deserialize, Serialize};
+use std::{
+    collections::HashSet, fmt::Write as _, fs::{File, OpenOptions}, io::{BufRead, BufReader, Read, Seek, Write as _}, path::{Path, PathBuf}
+};
+
+#[derive(Parser, Debug)]
+#[command(version, about, long_about = None)]
+struct Args {
+    notes: PathBuf,
+    patterns: Option<PathBuf>,
+}
 
 #[derive(Serialize, Deserialize, Debug)]
 enum Pattern {
-    Yearly { doy: u32 },
-    MonthlyOpt { dom: u32, months: Vec<chrono::Month> },
-    Monthly { dom: u32 },
-    Weekly { dow: u32 },
+    Yearly {
+        doy: u32,
+    },
+    MonthlyOpt {
+        dom: u32,
+        months: Vec<chrono::Month>,
+    },
+    Monthly {
+        dom: u32,
+    },
+    Weekly {
+        dow: u32,
+    },
     Daily,
 }
 
 #[derive(Serialize, Deserialize, Debug)]
 struct Position {
     name: String,
-    pattern: Pattern
+    pattern: Pattern,
 }
 
-fn parse_patterns() {
-    let f = fs::read_to_string("data/patterns.ron").expect("file should exist");
-    let patterns: Vec<Position> = ron::from_str(&f).expect("file should follow proper ron syntax");
-    dbg!(patterns);
-}
+fn update_notes(notes_path: &Path) {
+    let mut file = OpenOptions::new().read(true).write(true).open(notes_path).expect("file should exist");
+    let mut bufreader = BufReader::new(&file);
+    let mut linebuf = String::new();
+    let mut all_lines = String::new();
+    let mut latest_date = NaiveDate::MIN;
+    let mut lines_with_duplicates: Vec<usize> = Vec::new();
+
+    // Find todo-type lines
+    while let Ok(n) = bufreader.read_line(&mut linebuf) {
+        if n == 0 {
+            break;
+        }
+
+        let trimmed_str = linebuf.trim();
+        let trimmed_bytes = trimmed_str.as_bytes();
+        let Some(sub) = trimmed_bytes.get(0..5) else { continue; };
+        println!("cur line is {:?}. Sub is {:?}", trimmed_str, sub);
+        if sub == b"- [ ]" {
+            all_lines.push_str(&linebuf);
+        } else if trimmed_bytes.get(0) == Some(&b'#') {
+            if let Ok(date) = NaiveDate::parse_from_str(trimmed_str.get(1..).unwrap(), "%Y-%m-%d") {
+                if date > latest_date {
+                    latest_date = date;
+                }
+            }
+        }
+        linebuf.clear();
+    }
+
+    // Find duplicates
+    let mut todos_hashset: HashSet<&str> = HashSet::new();
+    for (idx, line) in all_lines.split("\n").enumerate() {
+        if !todos_hashset.insert(line) {
+            lines_with_duplicates.push(idx);
+        }
+    }
+
+    // Prepare buffer
+    let res1 = bufreader.seek(std::io::SeekFrom::End(-2));
+    let mut last_two_bytes = [0u8, 0u8];
+    let res2 = bufreader.read_exact(&mut last_two_bytes);
+    if last_two_bytes != *b"\n\n" {
+        write!(linebuf, "\n");
+    }
+
+    let today = Local::now().date_naive();
+    if latest_date < today {
+        writeln!(linebuf, "# {}", today);
+    }
 
-fn parse_notes() {
     
+    let mut cur = 0;
+    for (idx, line) in all_lines.split("\n").enumerate() {
+        if cur < lines_with_duplicates.len() && lines_with_duplicates[cur] == idx {
+            cur += 1;
+        } else {
+            writeln!(linebuf, "{line}");
+        }
+    }
+
+    println!("{:?}", file.write_all(linebuf.as_bytes()));
+
+    // TODO: Handle case if today already exists
+    // TODO: Dont put once-open but now closed todos in
+    
+    // Opt: Create new date for today
+    // Put all open todos into today
+}
+
+fn parse_patterns(notes_path: &Path, patterns_path: &Path) {
+    // Put all patternized todos into today
 }
 
 fn main() {
-    parse_patterns();
+    let args = Args::parse();
+
+    update_notes(&args.notes);
+    if let Some(patterns_path) = args.patterns {
+        parse_patterns(&args.notes, &patterns_path);
+    }
 }