Why “I'll Do It Tonight” Became the Default Plan

"I'll do it tonight" is a reasonable thing to say once. A proposal needs finishing, a quote needs checking, a report needs writing, and the day has been full. The evening is quiet. It gets done.

The question this piece is interested in is what happens when the sentence stops being an exception and becomes the plan. When the evening is no longer where work goes if the day overruns, but where certain kinds of work are expected to go every time. When nobody, including the person themselves, schedules the important task for 10:00, because everyone knows it will really happen at 20:30.

That shift is easy to miss, because it rarely involves a decision. It is a habit that forms around the way the working day is organised.

The evening as a planned shift

Microsoft researchers noticed a version of this pattern in their own workforce. In a 2021 WorkLab article on what they called the "triple peak day", they reported that about 30 percent of the Microsoft employees they studied showed a third spike of work activity in the evening, alongside the familiar morning and afternoon peaks. The same article reported a rise in Teams chats sent after hours.

That research describes one company's employees during a particular period, when hybrid work patterns were forming, and the authors noted that some of the evening activity reflected genuine flexibility, such as people fitting work around childcare. It should not be stretched into a claim about South African businesses. But it illustrates something worth taking seriously: the evening can become a structural part of the working day rather than an occasional overflow.

Why the day stops holding the work

The more useful question is why focused work migrates to the evening. Microsoft's 2023 Work Trend Index offers part of an answer. Based on Microsoft 365 activity data, it reported that people spent 57 percent of their time communicating, in meetings, email and chat, and 43 percent creating. In the accompanying survey, 68 percent said they did not have enough uninterrupted focus time during the workday, and 64 percent said they struggled to have the time and energy to do their job.

Those figures describe a large, global sample of software users, not any particular business. Read carefully, they suggest a mechanism rather than a verdict. If most of the day goes on responding to other people, the work that needs a clear run of attention gets pushed to whenever the responding stops. For many people, that is after hours.

In smaller businesses, the mechanism often has local causes: an owner who is also the main salesperson, an administrator who is also reception, a manager whose day is taken up by questions only they can answer. Each of these turns the working day into a series of interruptions and pushes the thinking work into the evening.

An illustrative case

Take an illustrative example, not a real business: a Nelspruit tourism operator with about a dozen staff, run by an owner who handles bookings, guides, suppliers and the website.

In this scenario, the owner's day is a steady stream of calls, WhatsApp messages and walk-in questions. Staff check with them before confirming anything unusual. Suppliers prefer to speak to the owner. By late afternoon, the tasks that need concentration, such as pricing next season, reviewing the month's figures or answering a complex group enquiry, are untouched.

So they are written on the evening list. Over time, the owner stops even trying to fit them into the day. The calendar shows meetings and site visits. The real planning is done at the kitchen table.

The owner would probably describe this as how things are in a small business. That may be partly true. It is also, in part, a consequence of how decisions and information are routed through one person.

The human tax

The first tax is time: evenings that are planned as working time, rather than occasionally borrowed.

The second is energy. The work that ends up in the evening is often the work that needs the most judgement: pricing, planning, writing, analysis. It is done after a full day of responding to others, which is not when most people think best.

The third is presence. When the evening is reserved for work, the hours before it are partly occupied by the knowledge that the "real" task is still waiting.

It is worth stating plainly that some people prefer working in the evening, and for them the arrangement may be a genuine choice. The concern here is with the evening as a default that the day has forced, not as a preference someone has chosen.

What could realistically change

The changes are mainly about protecting time during the day and reducing the volume of interruptions, rather than about working faster at night.

Find out where the day goes. A week of honest notes on interruptions, calls and questions usually shows a few repeated sources. Many of them have fixes: a decision that could be delegated, a question that could be answered in writing once.
Protect a block of focus time. A regular morning slot with messages silenced and colleagues aware of it. It sounds simple, and it works only if the rest of the business can function without the person for that time.
Delegate decisions with clear limits. If staff can confirm bookings or approve small exceptions within agreed rules, many interruptions disappear.
Clarify priorities. The WHO and ILO guidance on healthy telework recommends developing work plans and clarifying priorities, timelines and expected results. That advice translates well to any role where the day fills up with whatever arrives first.
Remove work, not just reschedule it. Some evening tasks exist because a report is rebuilt by hand or information is copied between systems. Fixing that removes the task rather than moving it; finding the manual work nobody is measuring is a practical place to start.

Mellorca has looked at where these interruptions come from in the cost of messages, notifications and context switching, and at how capable people end up spending their days on the wrong work in when your best people spend their day on low-value work.

What changes first, and for the business

The first change is that some of the thinking work moves back into the day. Pricing gets done on a Tuesday morning rather than a Tuesday night. Fewer tasks appear on the evening list.

For the business, decisions that need judgement get made with more attention, and the business becomes less dependent on one person's willingness to work late. Staff who can now decide more for themselves may also move faster.

The human dividend

The dividend is time and presence. When the day can hold the work, the evening returns to being the person's own, to spend however they choose. The hours before it are less shadowed by the task still waiting. Work that needs thought gets done when the person has thought to give.

Perhaps the clearest sign of the dividend is linguistic. "I'll do it tonight" becomes, again, something a person says occasionally, rather than a description of how every day ends.

The trade-offs

Protected time reduces availability. A focus block means colleagues and customers wait. Some will find that frustrating, and the business must decide that the wait is acceptable.
Delegation gives up control. Letting staff make decisions within limits means accepting that they will sometimes decide differently.
Evening flexibility has value. For some people, working in the evening is what makes school pickups, caring responsibilities or daytime activities possible. Removing that option would be a loss, not a dividend.
Change takes effort. Finding and fixing the sources of interruption is itself work, and it usually has to happen during the busy day it is trying to improve.

Why it matters

Evenings are where much of life outside work happens. When they become a planned extension of the working day, the cost is easy to normalise and hard to see.

Mellorca's reading is that "I'll do it tonight" is often a symptom of a working day designed around responding rather than thinking. Redesign the day, and the evening can go back to being a choice. A related Moment explores a similar drift at the end of the week: when Sunday evening becomes Monday morning.

Sources and further reading

https://www.microsoft.com/en-us/worklab/triple-peak-day (last verified 10 October 2026)
https://www.microsoft.com/en-us/worklab/work-trend-index/will-ai-fix-work (last verified 10 October 2026)
Crucial changes needed to protect workers’ health while teleworking (last verified 10 October 2026)