Skip to main content
U.S. flag

An official website of the United States government

Here’s how you know

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

HTTPS

Secure .gov websites use HTTPS
A lock (LockA locked padlock) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

    • Environmental Topics
    • Air
    • Bed Bugs
    • Cancer
    • Chemicals, Toxics, and Pesticide
    • Emergency Response
    • Environmental Information by Location
    • Health
    • Land, Waste, and Cleanup
    • Lead
    • Mold
    • Radon
    • Research
    • Science Topics
    • Water Topics
    • A-Z Topic Index
    • Laws & Regulations
    • By Business Sector
    • By Topic
    • Compliance
    • Enforcement
    • Laws and Executive Orders
    • Regulations
    • Report a Violation
    • Environmental Violations
    • Fraud, Waste or Abuse
    • About EPA
    • Our Mission and What We Do
    • Headquarters Offices
    • Regional Offices
    • Labs and Research Centers
    • Planning, Budget, and Results
    • Organization Chart
    • EPA History

Breadcrumb

  1. Home
  2. High-End Scientific Computing
  3. RETIGO

Tutorial: Create a RETIGO File from an Excel Spreadsheet

RETIGO TIP
  • Problems running RETIGO? Try clearing your browser cache and restarting.

This page contains both video and interactive tutorials that will show you how to take an Excel spreadsheet and convert it into a valid RETIGO input file.

Start by downloading this Retigo Example Spreadsheet (xlsx) (39.51 KB) .

  • Video Tutorial
  • Interactive Tutorial

Video Tutorial


This video tutorial will show you how to create a RETIGO file from an Excel spreadsheet. You can also read through the regular tutorial material below. The video is narrated, so be sure your sound is on.

  • Video: Creating a RETIGO file (WMV) (13:59, 19.7 MB, 960x540)
  • Video: Creating a RETIGO file (MP4) (13:59, 21,1 MB, 960x540)

Interactive Tutorial

When you open the example in Excel, you will notice that it is similar to a RETIGO file in terms of the columns of data, and yet it differs in a couple of ways. First and most importantly, the timestamp does not conform to the ISO-8601 standard. Instead, the timestamp is given in Excel's internal timekeeping system (aka "Excel serial time"). Also, the column headings are incomplete.

Image showing time stamp format for Excel

The simplest way to generate the appropriate timestamps is to use RETIGO's timestamp converter tool. Just select the timestamp column, copy it, and paste it into the left-hand side of the timestamp converter tool.

Image displaying copy function in Excel
Image showing paste function in Excel

The next step is to choose the type of timestamp that you have. In this case it is "Excel serial time (1900 date system)", because the computer that generated the Excel file used that date system. For more information on the two date systems that Excel uses, see the Microsoft Support page Date systems in Excel.  

Certain time formats (such as UNIX and IGOR) are always referenced against the GMT timezone, while others (such as Excel time) could be relative to any timezone. If you need to specify the timezone, the "Original Timezone" menu will appear. In this example, the original timezone was Eastern Standard Time (EST), corresponding to a November, 2008 data collection in Raleigh, NC.

The "Output Timezone" is strictly optional, but is provided as a convenience if you prefer to "think" relative to a certain timezone. In this case, we selected EST so that the base time in the generated ISO-8601 timestamps is relative to EST. No matter what output timezone is selected, the ISO-8601 timestamp will refer to the same instant in time because the appropriate GMT offset will automatically be created.

Once the selections are made, press the Convert button to generate the list of converted timestamps:

Image showing Convert button to generate the list

Image showing Convert button.

The next step is to copy the list of converted timestamps and paste them into a new column in the Excel spreadsheet:

Image displaying adding a new column in Excel

Image showing adding a new column.

Renaming column header in Excel


 While we are at it, we might as well add units to the other data columns so RETIGO will be able to display them properly:

Adding data units to columns
Finally, we just delete the original timestamp column (Column A) and export the spreadsheet as a "Windows Comma Separated" (.csv) file that can be imported into RETIGO. Done! 

High-End Scientific Computing

  • RSIG
    • Download
    • RSIG3D Release History
    • RSIG3D Video Demonstrations
    • Web Access to RSIG Data
    • Reading Local/Remote CMAQ Files
    • Data Inventory
    • RSIG-Related Downloadable Data Files
    • How RSIG Regrids Data
    • Troubleshooting RSIG
  • EDM
    • About Estuary Data Mapper
    • Download & Install
    • Image Gallery
    • Release History
    • Data Inventory
    • Frequent Questions
    • Special Topics and Videos
      • EDM Basics
      • Nitrogen Sources and Loads
      • Develop Seagrass Models
      • Seagrass Updates (2024)
      • Web Coverage Service (WCS)
      • WCS & Decision Support Tools
      • Land-Use Scenarios
  • RETIGO
    • Enter Your Data in RETIGO
    • Timestamp Converter
    • Tutorial: How to use RETIGO
    • Tutorial: Create RETIGO file from Excel
    • Frequent Questions
Contact Us About High-End Scientific Computing
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on May 12, 2025
  • Assistance
  • Spanish
  • Arabic
  • Chinese (simplified)
  • Chinese (traditional)
  • French
  • Haitian Creole
  • Korean
  • Portuguese
  • Russian
  • Tagalog
  • Vietnamese
United States Environmental Protection Agency

Discover.

  • Accessibility Statement
  • Budget & Performance
  • Contracting
  • EPA www Web Snapshot
  • Grants
  • No FEAR Act Data
  • Plain Writing
  • Privacy
  • Privacy and Security Notice

Connect.

  • Data
  • Inspector General
  • Jobs
  • Newsroom
  • Regulations.gov
  • Subscribe
  • USA.gov
  • White House

Ask.

  • Contact EPA
  • EPA Disclaimers
  • Hotlines
  • FOIA Requests
  • Frequent Questions
  • Site Feedback

Follow.

Environmental Protection Agency logo
www.epa.gov Feedback Survey

Welcome! Please share your feedback on how we can make www.epa.gov work better for you.

A red asterisk (*) indicates a required field.

Success

Thank you. Your feedback has been received.

Error

alert message

Required Questions - page 1 of 2
question_55203_answer_01
*

400 characters allowed
Would you like to take two more minutes to answer more questions to help us improve our services?
Yes, keep going →
← Back
Optional questions - page 2 of 2
How would you describe yourself?
400 characters allowed
400 characters allowed
400 characters allowed
U.S. flag

An official form of the United States government. Provided by Touchpoints
OMB Approval #1090-0008 · Expiration Date 11/30/2027