diff --git a/Cargo.lock b/Cargo.lock
index c51c076..ef02a81 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -73,6 +73,12 @@ version = "1.4.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "14c189c53d098945499cdfa7ecc63567cf3886b3332b312a5b4585d8d3a6a610"
 
+[[package]]
+name = "cfg-if"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+
 [[package]]
 name = "chrono"
 version = "0.4.19"
@@ -86,6 +92,28 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "chrono-tz"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "64c01c1c607d25c71bbaa67c113d6c6b36c434744b4fd66691d711b5b1bc0c8b"
+dependencies = [
+ "chrono",
+ "chrono-tz-build",
+ "phf",
+]
+
+[[package]]
+name = "chrono-tz-build"
+version = "0.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "db058d493fb2f65f41861bfed7e3fe6335264a9f0f92710cab5bdf01fef09069"
+dependencies = [
+ "parse-zoneinfo",
+ "phf",
+ "phf_codegen",
+]
+
 [[package]]
 name = "clap"
 version = "2.33.3"
@@ -125,6 +153,17 @@ dependencies = [
  "typenum",
 ]
 
+[[package]]
+name = "getrandom"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7fcd999463524c52659517fe2cea98493cfe485d10565e7b0fb07dbba7ad2753"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi",
+]
+
 [[package]]
 name = "heck"
 version = "0.3.3"
@@ -186,6 +225,15 @@ version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2839e79665f131bdb5782e51f2c6c9599c133c6098982a54c794358bf432529c"
 
+[[package]]
+name = "parse-zoneinfo"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c705f256449c60da65e11ff6626e0c16a0a0b96aaa348de61376b249bc340f41"
+dependencies = [
+ "regex",
+]
+
 [[package]]
 name = "pest"
 version = "2.1.3"
@@ -229,6 +277,51 @@ dependencies = [
  "sha-1",
 ]
 
+[[package]]
+name = "phf"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b9fc3db1018c4b59d7d582a739436478b6035138b6aecbce989fc91c3e98409f"
+dependencies = [
+ "phf_shared",
+]
+
+[[package]]
+name = "phf_codegen"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4fb1c3a8bc4dd4e5cfce29b44ffc14bedd2ee294559a294e2a4d4c9e9a6a13cd"
+dependencies = [
+ "phf_generator",
+ "phf_shared",
+]
+
+[[package]]
+name = "phf_generator"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5d5285893bb5eb82e6aaf5d59ee909a06a16737a8970984dd7746ba9283498d6"
+dependencies = [
+ "phf_shared",
+ "rand",
+]
+
+[[package]]
+name = "phf_shared"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b6796ad771acdc0123d2a88dc428b5e38ef24456743ddb1744ed628f9815c096"
+dependencies = [
+ "siphasher",
+ "uncased",
+]
+
+[[package]]
+name = "ppv-lite86"
+version = "0.2.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ed0cfbc8191465bed66e1718596ee0b0b35d5ee1f41c5df2189d0fe8bde535ba"
+
 [[package]]
 name = "proc-macro-error"
 version = "1.0.4"
@@ -271,6 +364,61 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "rand"
+version = "0.8.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2e7573632e6454cf6b99d7aac4ccca54be06da05aca2ef7423d22d27d4d4bcd8"
+dependencies = [
+ "libc",
+ "rand_chacha",
+ "rand_core",
+ "rand_hc",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6c10a63a0fa32252be49d21e7709d4d4baf8d231c2dbce1eaa8141b9b127d88"
+dependencies = [
+ "ppv-lite86",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.6.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d34f1408f55294453790c48b2f1ebbb1c5b4b7563eb1f418bcfcfdbb06ebb4e7"
+dependencies = [
+ "getrandom",
+]
+
+[[package]]
+name = "rand_hc"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d51e9f596de227fda2ea6c84607f5558e196eeaf43c986b724ba4fb8fdf497e7"
+dependencies = [
+ "rand_core",
+]
+
+[[package]]
+name = "regex"
+version = "1.5.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d07a8629359eb56f1e2fb1652bb04212c072a87ba68546a04065d525673ac461"
+dependencies = [
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.6.25"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f497285884f3fcff424ffc933e56d7cbca511def0c9831a7f9b5f6153e3cc89b"
+
 [[package]]
 name = "sha-1"
 version = "0.8.2"
@@ -283,6 +431,12 @@ dependencies = [
  "opaque-debug",
 ]
 
+[[package]]
+name = "siphasher"
+version = "0.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "533494a8f9b724d33625ab53c6c4800f7cc445895924a8ef649222dcb76e938b"
+
 [[package]]
 name = "strsim"
 version = "0.8.0"
@@ -370,6 +524,7 @@ version = "0.1.0"
 dependencies = [
  "anyhow",
  "chrono",
+ "chrono-tz",
  "pest",
  "pest_derive",
  "structopt",
@@ -388,6 +543,15 @@ version = "0.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "56dee185309b50d1f11bfedef0fe6d036842e3fb77413abef29f8f8d1c5d4c1c"
 
+[[package]]
+name = "uncased"
+version = "0.9.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5baeed7327e25054889b9bd4f975f32e5f4c5d434042d59ab6cd4142c0a76ed0"
+dependencies = [
+ "version_check",
+]
+
 [[package]]
 name = "unicode-segmentation"
 version = "1.8.0"
diff --git a/Cargo.toml b/Cargo.toml
index 7a4ee3d..ebe71f7 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -6,6 +6,7 @@ edition = "2018"
 [dependencies]
 anyhow = "1.0.45"
 chrono = "0.4.19"
+chrono-tz = "0.6.0"
 pest = "2.1.3"
 pest_derive = "2.1.0"
 structopt = "0.3.25"
diff --git a/src/files.rs b/src/files.rs
new file mode 100644
index 0000000..392525a
--- /dev/null
+++ b/src/files.rs
@@ -0,0 +1,59 @@
+use std::collections::HashMap;
+use std::path::{Path, PathBuf};
+use std::{fs, io, result};
+
+use chrono_tz::Tz;
+
+use crate::commands::File;
+use crate::parse;
+
+#[derive(Debug)]
+pub struct Files {
+    files: HashMap<PathBuf, File>,
+    timezone: Option<Tz>,
+}
+
+#[derive(Debug, thiserror::Error)]
+pub enum Error {
+    #[error("{0}")]
+    IoError(#[from] io::Error),
+    #[error("{0}")]
+    ParseError(#[from] parse::Error),
+}
+
+pub type Result<T> = result::Result<T, Error>;
+
+impl Files {
+    pub fn load(path: &Path) -> Result<Self> {
+        let mut new = Self {
+            files: HashMap::new(),
+            timezone: None,
+        };
+
+        new.load_file(path)?;
+        new.determine_timezone()?;
+
+        Ok(new)
+    }
+
+    fn load_file(&mut self, path: &Path) -> Result<()> {
+        let canon_path = path.canonicalize()?;
+        if self.files.contains_key(&canon_path) {
+            // We've already loaded this exact file.
+            return Ok(());
+        }
+
+        let content = fs::read_to_string(path)?;
+        let file = parse::parse(path, &content)?;
+        self.files.insert(canon_path, file);
+
+        // TODO Also load all imported files
+
+        Ok(())
+    }
+
+    fn determine_timezone(&mut self) -> Result<()> {
+        // TODO Implement once files can specify time zones
+        Ok(())
+    }
+}
diff --git a/src/main.rs b/src/main.rs
index b1f788c..1cec2d7 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,13 +1,12 @@
-use std::fs;
 use std::path::PathBuf;
 
-use chrono::NaiveDate;
 use structopt::StructOpt;
 
-use crate::eval::entries::DateRange;
+use crate::files::Files;
 
 mod commands;
 mod eval;
+mod files;
 mod format;
 mod parse;
 
@@ -19,15 +18,7 @@ pub struct Opt {
 
 fn main() -> anyhow::Result<()> {
     let opt = Opt::from_args();
-    let content = fs::read_to_string(&opt.file)?;
-    let file = parse::parse(&opt.file, &content)?;
-    let entries = eval::eval(
-        &file,
-        DateRange::new(
-            NaiveDate::from_ymd(2021, 1, 1),
-            NaiveDate::from_ymd(2021, 12, 31),
-        ),
-    )?;
-    println!("{:#?}", entries);
+    let files = Files::load(&opt.file)?;
+    println!("{:#?}", files);
     Ok(())
 }
diff --git a/src/parse.rs b/src/parse.rs
index 9d9cae4..2dbe5df 100644
--- a/src/parse.rs
+++ b/src/parse.rs
@@ -2,7 +2,7 @@ use std::path::Path;
 use std::result;
 
 use chrono::NaiveDate;
-use pest::error::{Error, ErrorVariant};
+use pest::error::ErrorVariant;
 use pest::iterators::Pair;
 use pest::prec_climber::{Assoc, Operator, PrecClimber};
 use pest::{Parser, Span};
@@ -16,9 +16,10 @@ use crate::commands::{
 #[grammar = "parse/todayfile.pest"]
 struct TodayfileParser;
 
-type Result<T> = result::Result<T, Error<Rule>>;
+pub type Error = pest::error::Error<Rule>;
+pub type Result<T> = result::Result<T, Error>;
 
-fn error<S: Into<String>>(span: Span, message: S) -> Error<Rule> {
+fn error<S: Into<String>>(span: Span, message: S) -> Error {
     Error::new_from_span(
         ErrorVariant::CustomError {
             message: message.into(),