I’m working with a Google Sheets spreadsheet that tracks time intervals with start times, end times, and calculated durations.
Begin Finish Total Time
23:45 02:15 02:30
08:30 12:45 04:15
14:20 18:05 03:45
19:15 23:59 04:44
When I calculate the total time by finding the difference between finish and begin times, everything seems fine for individual rows. However, when I attempt to sum up all the values in the Total Time column, I frequently end up with huge negative results instead of the expected positive total.
Additionally, I’m struggling with creating a summary that filters this data by date ranges. For example, I want to create a separate sheet that automatically calculates the combined duration for entries from the past month. What would be the best approach to handle these time calculations and date-based filtering? Any help would be appreciated.
Midnight calculations in Sheets are a nightmare. Google sees 02:15 as earlier than 23:45, so you get negative durations that break everything.
I hit this same issue tracking server maintenance across midnight. Tried all sorts of MOD and IF workarounds, but here’s what actually works: ditch separate time columns and use full timestamps instead. So “2024-01-15 23:45:00” to “2024-01-16 02:15:00”. Your duration formula becomes dead simple: =B2-A2 with [h]:mm formatting.
This also fixes your date filtering headaches. SUMIFS works normally since you can filter by date while the time math stays correct. Sheets handles datetime arithmetic perfectly - it’s the time-only format that screws things up.
You can convert your existing data by adding a date column and combining it with your times using DATE and TIME functions. Bit of upfront work, but it kills all midnight problems for good.
You’re experiencing difficulties calculating total time durations in Google Sheets when those durations span midnight, resulting in large negative values in your sum. You also need a method to efficiently filter and summarize this data by date ranges (e.g., the past month). The current approach uses separate time columns, which complicates calculations and filtering.
Understanding the “Why” (The Root Cause):
Google Sheets handles times as fractions of a day. When a time interval crosses midnight (e.g., 23:45 to 02:15), the end time is interpreted as earlier than the start time, leading to negative durations. Summing these negative durations results in the large negative totals you observe. Using separate time columns without date information makes it difficult to apply date-based filters accurately.
Step-by-Step Guide:
Use Full Timestamps: The most effective solution is to represent your time intervals using full timestamps (date and time) instead of separate time columns. This allows Google Sheets to correctly handle time calculations across midnight.
Convert Existing Data: If you have existing data, add a new column (“Date”) and use formulas to combine existing “Begin” and “Finish” times with the appropriate dates. For example, assuming “Begin” and “Finish” times are in columns A and B and the corresponding date is in column C:
Adjust the DATE function as needed to capture the correct date for each row. Note that this example assumes the same date for “Begin” and “Finish” times in each row. If your “Begin” and “Finish” time can span multiple days, you’ll need a more sophisticated approach that accounts for this.
New Data Entry: For new data entries, always include both date and time. This ensures correct calculations from the beginning.
Calculate Durations: Now that you’re using full timestamps, calculating durations becomes straightforward. If your timestamps are in columns D and E, this formula in column F will calculate durations correctly:
=E2-D2
Format column F as “Duration” to display the results in hours and minutes. The “[h]:mm:ss” format is recommended to handle durations exceeding 24 hours.
Implement Date-Based Filtering and Summarization: To create a summary sheet for the past month, use SUMIFS to filter your data by date and sum the durations:
This formula sums the durations (column F) where the timestamps (column D) are within the past month.
Common Pitfalls & What to Check Next:
Date and Time Formatting: Double-check that your date and time columns are formatted correctly. Incorrect formatting can lead to errors in calculations.
Error Handling: Consider adding error handling to your formulas to manage potential inconsistencies in your data (e.g., empty cells or invalid entries).
Data Validation: Implement data validation to ensure consistency in how date and time data is entered.
Still running into issues? Share your (sanitized) config files, the exact command you ran, and any other relevant details. The community is here to help!
Google Sheets treats times as fractions of a day, so when you sum durations that cross midnight, it breaks.
You could try cell formatting and TEXT functions, but that gets messy once you add date filtering.
I hit this same issue tracking deployment windows across time zones. Wasted hours on Google Sheets formulas before realizing I was overcomplicating it.
I set up automation in Latenode that pulls raw time data from sheets, handles duration calculations correctly (including midnight crossovers), and pushes clean totals to a summary sheet.
For date filtering, Latenode auto-updates different sheets based on your criteria - past month, past week, specific ranges. No complex SUMIFS needed.
Best part? It runs automatically. Your summaries stay current without manual refreshing or formulas breaking when you add data.
I’ve dealt with this exact nightmare tracking overnight shifts. Google Sheets treats times as decimal fractions of 24 hours, so it freaks out when times cross midnight. Quick fix: wrap your time difference in MOD function like =MOD(B2-A2,1). This handles the midnight crossover without breaking. For your totals, make sure you’re using [h]:mm format instead of regular time format - otherwise your sums will be wrong. For date filtering, I just add a separate date column next to my time entries. Then use SUMIFS like =SUMIFS(Total_Time_Range, Date_Range, “>=”&(TODAY()-30), Date_Range, “<=”&TODAY()) to get monthly totals. Fair warning: test your formulas on dummy data first. Time calculations love to look correct while being completely wrong by hours. Learned this the hard way.
Yeah, midnight calculations in Google Sheets are a pain. Had the same headache building a freelance timesheet. The issue is Sheets thinks 02:15 comes before 23:45, so you get negative numbers. I fixed it with a helper column that adds 1 when the end time is smaller than start time: =IF(B2<A2,B2+1,B2)-A2. For those massive negative totals, check your format - use [h]:mm not regular time format. Those brackets let hours go past 24. And honestly? Use full timestamps instead of just times. You can still display time-only but calculate with the full datetime. Makes filtering way easier and kills most midnight problems.
you’ve got to check the formatting, especially the 24hr format. use [h]:mm to make sure it calculates right. for the sum, the =TEXT() function can help with those negatives. hope this helps!
Ugh, same thing happened to me tracking work hours. Sheets can’t figure out when times cross midnight. Use =IF(C2<B2,C2+1-B2,C2-B2) for the duration calculation. Also make sure your sum formula isn’t accidentally grabbing the text headers.
Understanding the “Why” (The Root Cause):
Step-by-Step Guide:
Common Pitfalls & What to Check Next:
Still running into issues? Share your (sanitized) config files, the exact command you ran, and any other relevant details. The community is here to help!